Patent Application
20240146031
The technology according to the present disclosure (hereinafter also referred to as “the present technology”) relates to a surface emitting laser and an electronic device.
Conventionally, surface emitting lasers in which a resonator including an active layer is disposed between first and second multilayer film reflectors are known. Some surface emitting lasers are provided with a buried tunnel junction (BTJ) structure in a resonator (see, for example, Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-Open No. 2006-508550
However, in the conventional surface emitting laser, in order to form the BTJ structure, etching of the tunnel junction layer (TJ layer) and subsequent embedded regrowth are required, and the number of manufacturing steps is increased.
Therefore, a main object of the present technology is to provide a surface emitting laser that does not require etching of a tunnel junction layer (TJ layer) and subsequent embedded regrowth and can reduce the number of manufacturing steps.
The present technology provides a surface emitting laser including:
The resonator may include a cladding layer between the tunnel junction layer and the active layer, and in the cladding layer, at least a peripheral portion of a portion on a side of the tunnel junction layer may have higher resistance than a central portion.
The cladding layer may be a p-type semiconductor layer.
The cladding layer may be constituted by a p-type InP-based compound semiconductor.
In the active layer, at least a peripheral portion of a portion on a side of the tunnel junction layer may have higher resistance than a central portion.
The resonator may include a cladding layer on a side of the active layer opposite to a side of the tunnel junction layer, and the cladding layer may have a lower resistance than a peripheral portion of the tunnel junction layer.
An electrode may be provided on the cladding layer.
The cladding layer may be an n-type semiconductor layer.
The cladding layer may be constituted by an n-type InP-based compound semiconductor.
The resonator may include a cladding layer on a side of the tunnel junction layer opposite to a side of the active layer, and the cladding layer may have a lower resistance than a peripheral portion of the tunnel junction layer.
An electrode may be provided on the cladding layer.
The cladding layer may be an n-type semiconductor layer.
The cladding layer may be constituted by an n-type InP compound semiconductor.
A peripheral portion of the resonator may be increased in resistance by ion implantation at least in an entire region in a thickness direction of the tunnel junction layer.
An impurity concentration in the ion implantation may be less than 1×1019 cm−3.
Impurity in the ion implantation may include at least one of H, B, C, or O.
The tunnel junction layer may include a p-type semiconductor region and an n-type semiconductor region, and each of the p-type semiconductor region and the n-type semiconductor region may be constituted by any of an InP-based compound semiconductor, an AlGaInAs-based compound semiconductor, and an AlGaInSbAs-based compound semiconductor.
The imaging device may further include a substrate disposed between the resonator and a reflector closer to the active layer than the tunnel junction layer among the first and second reflectors, and the reflector may be a concave multilayer film reflector.
The thermal conductivity of the substrate may be 40 W/m·K or more.
The present technology also provides an electronic device including the surface emitting laser.
Hereinafter, preferred embodiments of the present technology will be described in detail with reference to the accompanying drawings. Note that, in the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals to avoid the description from being redundant. The embodiments described below illustrate representative embodiments of the present technology, and the scope of the present technology is not to be narrowly interpreted according to these embodiments. In the present specification, even in a case where it is described that a surface emitting laser and an electronic device according to the present technology exhibits a plurality of effects, it is sufficient if the surface emitting laser and the electronic device according to the present technology exhibits at least one effect. The effects described herein are merely examples and are not limited, and other effects may be provided.
Furthermore, the description will be given in the following order.
In recent years, infrared-surface emitting lasers used for 3D sensing and face authentication have been developed. At present, for example, a 940 nm band is mainly used as an oscillation wavelength in an infrared-surface emitting laser, but a further longer wavelength is desired in the future. In particular, for example, the 1.4 pm band is an eye safe band in which the damage threshold to the eye greatly increases, and has an advantage that noise at the time of sensing can be suppressed low because the intensity of sunlight is low.
On the other hand, an InP-based surface emitting laser suitable for a long wavelength of, for example, 1.3 pm or more as an oscillation wavelength has a problem that it is difficult to produce a current confinement structure by oxidation of an AlAs layer used in, for example, a GaAs-based surface emitting laser. For this reason, in the InP-based surface emitting laser, a buried tunnel junction (BTJ) structure is frequently used as a current confinement structure, but in this BTJ structure, etching of a tunnel junction layer (TJ layer) and subsequent embedded regrowth are required, and the number of steps increases.
Therefore, the inventors have developed a surface emitting laser represented by, for example, an InP-based surface emitting laser having a current confinement structure, which can be manufactured with a small number of steps without requiring both etching and subsequent embedded regrowth.
As an example, as illustrated in
The surface emitting laser 100 is driven by, for example, a laser driver.
In the surface emitting laser 100, as an example, the resonator R and the first reflector 108 are arranged in this order from the substrate 130 side on the front surface (upper surface) of the substrate 130, and the second reflector 102 is provided on the back surface (lower surface) of the substrate 130.
In the surface emitting laser 100, as an example, a mesa M including a part (upper portion) of the resonator R is formed on the substrate 130. The mesa M has, for example, a substantially cylindrical shape, but may have another shape such as a substantially elliptical columnar shape, a polygonal columnar shape, a truncated cone shape, an elliptical frustum shape, or a polygonal frustum shape. A height direction of the mesa M substantially coincides with a stacking direction (vertical direction) of each of the constituent layers of the surface emitting laser 100.
As an example, the surface emitting laser 100 emits light from the upper surface (emission surface) of the first reflector 108 provided at the top portion of the mesa M. That is, as an example, the surface emitting laser 100 is a front surface emitting type surface emitting laser.
The substrate 130 is disposed between the resonator R and the second reflector 102 which is a reflector closer to an active layer 104 described later than a tunnel junction layer 106 among the first and second reflectors 108 and 102. Since the substrate 130 is a substrate for forming the second reflector 102 when the surface emitting laser 100 is manufactured as described later, it is also referred to as a “reflector forming substrate 130”.
The substrate 130 is, for example, a semiconductor substrate such as a GaAs substrate, a Si substrate, or a SiC substrate. The thermal conductivity of the substrate 130 is preferably, for example, 40 W/m·K or more.
The first reflector 108 is, for example, a dielectric multilayer film reflector. As a material of the dielectric multilayer film reflector, for example, SiO2, TiO2, Ta2O5, a-Si, Al2O3, or the like can be used.
As an example, the second reflector 102 is a concave dielectric multilayer film reflector, and is provided on the back surface (lower surface) of the substrate 130. As a material of the dielectric multilayer film reflector, for example, SiO2, TiO2, Ta2O5, a-Si, Al2O3, or the like can be used. The reflectance of the second reflector 102 is set slightly higher than that of the first reflector 108.
The resonator R includes the active layer 104 and the tunnel junction layer 106. Here, the active layer 104 is disposed on the substrate 130 side (lower side) of the tunnel junction layer 106. That is, the tunnel junction layer 106 is disposed on the upstream side of a current path from the anode electrode 109 to the cathode electrode 110 described later with respect to the active layer 104. Further, the resonator R includes a first cladding layer 105 between the tunnel junction layer 106 and the active layer 104. Further, the resonator R includes a second cladding layer 103 on the side of the active layer 104 opposite to the tunnel junction layer 106 side. Further, the resonator R includes a third cladding layer 107 on the side opposite to the active layer 104 side of the tunnel junction layer 106.
That is, in the resonator R, the second cladding layer 103, the active layer 104, the first cladding layer 105, the tunnel junction layer 106, and the third cladding layer 107 are arranged in this order from the substrate 130 side (lower side).
As an example, the active layer 105 has a quantum well structure including a barrier layer constituted by an AlGaInAs-based compound semiconductor and a quantum well layer. This quantum well structure may be a single quantum well structure (QW structure) or a multiple quantum well structure (MQW structure).
The tunnel junction layer 106 includes a p-type semiconductor region 106a and an n-type semiconductor region 106b arranged in contact with each other. Here, the p-type semiconductor region 106a is arranged on the substrate 130 side (lower side) of the n-type semiconductor region 106b.
The p-type semiconductor region 106a is constituted by, for example, a p-type AlGaInAs-based compound semiconductor highly doped with C, Mg, or Zn. The n-type semiconductor region 106b is constituted by, for example, an InP-based compound semiconductor or an AlGaInAs-based compound semiconductor highly doped with Si.
The first cladding layer 105 is, for example, a p-type semiconductor layer, and is constituted by, for example, a p-type InP-based compound semiconductor.
The second cladding layer 103 is, for example, an n-type semiconductor layer, and is constituted by, for example, an n-type InP-based compound semiconductor. On the second cladding layer 103, as an example, a cathode electrode 110 having a circular shape (for example, a ring shape) is provided so as to surround the mesa M via an insulating film 111 provided on a side surface of the mesa M. The insulating film 111 is constituted by a dielectric such as SiO2, SiN, or SiON. The cathode electrode 110 is constituted by, for example, Au/Ni/AuGe, Au/Pt/Ti, or the like. The cathode electrode 110 is electrically connected to, for example, a cathode (negative electrode) of the laser driver.
The third cladding layer 107 is, for example, an n-type semiconductor layer, and is constituted by, for example, an n-type InP-based compound semiconductor. As an example, the first reflector 108 is provided on the central portion of the third cladding layer 107, and the anode electrode 109 having a circular shape (ring shape) is provided on the peripheral portion so as to surround the first reflector 108. The anode electrode 109 is constituted by, for example, Au/Ni/AuGe, Au/Pt/Ti, or the like. The anode electrode 109 is electrically connected to, for example, an anode (positive electrode) of the laser driver.
In the resonator R, a part (for example, an intermediate portion) in the thickness direction (stacking direction, vertical direction, height direction of mesa M) of the peripheral portion is a current confinement region CCR (a portion colored in gray in
More specifically, in the resonator R, the peripheral portion has higher resistance than the central portion in the entire region in the thickness direction of the tunnel junction layer 106. Furthermore, in the resonator R, the peripheral portion has higher resistance than the central portion in the entire region in the thickness direction of the first cladding layer 105. Furthermore, in the resonator R, the peripheral portion has higher resistance than the central portion in the entire region in the thickness direction of the active layer 104. Furthermore, in the resonator R, the central portion and the peripheral portion of the second cladding layer 103 have lower resistance than the peripheral portion of the tunnel junction layer 106. Furthermore, in the resonator R, the third cladding layer 107 has lower resistance than the peripheral portion of the tunnel junction layer 106.
That is, here, the current confinement region CCR includes a peripheral portion of the tunnel junction layer 106, a peripheral portion of the first cladding layer 105, and a peripheral portion of the active layer 104.
More specifically, the peripheral portion of the resonator R is increased in resistance by ion implantation in the entire region in the thickness direction of each of the tunnel junction layer 106, the first cladding layer 105, and the active layer 104.
The impurity concentration in the ion implantation is preferably less than 1×1019 cm−3.
The impurity in the ion implantation preferably includes at least one of H, B, C, or O.
In the surface emitting laser 100, for example, the current supplied from the laser driver and flowing from the anode electrode 109 into the third cladding layer 107 is injected into the active layer 104 while being narrowed in the current confinement region CCR, and the active layer 104 emits light. The current that has passed through the active layer 104 passes through the second cladding layer 103 and flows out from the cathode electrode 110 to, for example, the laser driver. The light generated in the active layer 104 reciprocates between the first and second reflectors 108 and 102, is amplified in the active layer 104 during the reciprocation, and is emitted as laser light from the upper surface (emission surface) of the first reflector 108 when an oscillation condition is satisfied.
Hereinafter, a first example of the method for manufacturing the surface emitting laser 100 will be described with reference to the flowchart (steps S1 to S16) of
As an example, the surface emitting laser 100 is manufactured by the CPU of the semiconductor manufacturing apparatus according to the procedure of the flowchart of
In step S1, a laminate generation process (for example, a laminate generation process 1 described later) is performed. In the laminate generation process, as an example, each constituent layer of the surface emitting laser 100 is sequentially laminated (epitaxially grown) on a growth substrate 101 (for example, InP substrate) in a growth chamber by a metal organic chemical vapor deposition method (MOCVD method) or a molecular beam epitaxy method (MBE method) to generate a laminate (for example, a laminate L1). That is, in the laminate generation process, a laminate is generated by single epitaxial growth.
Hereinafter, the laminate generation process 1 as an example of the laminate generation process will be described with reference to the flowchart (steps T1-1 to T1-6) of
In the first step T1-1, as an example, the second cladding layer 103 (for example, an n-InP layer) is grown as a first n-type semiconductor layer on the growth substrate 101 (for example, an InP substrate).
In the next step T1-2, the active layer 104 is grown on the second cladding layer 103.
In the next step T1-3, the first cladding layer 105 (for example, a p-InP layer) is grown as a p-type semiconductor layer on the active layer 104.
In the next step T1-4, the p-type semiconductor region 106a of the tunnel junction layer 106 is grown on the first cladding layer 105.
In the next step T1-5, the n-type semiconductor region 106b of the tunnel junction layer 106 is grown on the p-type semiconductor region 106a.
In the final step T1-6, the third cladding layer 107 (for example, an n-InP layer) is grown as a second n-type semiconductor layer on the n-type semiconductor region 106b. As a result, the laminate L1 (see
In step S2, a protective film PF is formed on the laminate L1 (see
In step S3, ion implantation is performed (see
In step S4, the protective film PF is removed (see
In step S5, the mesa M is formed (see
In step S6, the first reflector 108 is formed (see
In step S7, the anode electrode 109 is formed (see
In step S8, the insulating film 111 is formed (see FIG. 11). Specifically, the insulating film 111 constituted by, for example, SiO2 or the like is formed so as to cover the first reflector 108, the anode electrode 109, the side surface of the mesa M, and the peripheral region of the mesa M.
In step S9, a part of the insulating film 111 is removed (see
In step S10, the cathode electrode 110 is formed (see
In step S11, a support substrate 120 is attached (see
In step S12, the growth substrate 101 is removed (see
In step S13, the reflector forming substrate 130 is attached (see
In step S14, the second reflector 102 is formed on the reflector forming substrate 130 (see
In step S15, the support substrate 120 is removed (see
In step S16, an annealing treatment is performed (see
The annealing treatment here can also serve as a sinter for each electrode. When step S16 is executed, the flow of
Hereinafter, a second example of the method for manufacturing the surface emitting laser 100 will be described with reference to the flowchart (steps S11 to S26) of
As an example, the surface emitting laser 100 is manufactured by the CPU of the semiconductor manufacturing apparatus according to the procedure of the flowchart of
In step S11, a laminate generation process (for example, the laminate generation process 1 described above) is performed. In the laminate generation process, as an example, each constituent layer of the surface emitting laser 100 is sequentially laminated (epitaxially grown) on a growth substrate 101 (for example, InP substrate) in a growth chamber by a metal organic chemical vapor deposition method (MOCVD method) or a molecular beam epitaxy method (MBE method) to generate a laminate (for example, a laminate L1). That is, in the laminate generation process, a laminate is generated by single epitaxial growth.
In step S12, the mesa M is formed (see
In step S13, the protective film PF is formed on the mesa M (see
In step S14, ion implantation is performed (see
In step S15, the protective film PF is removed (see
In step S16, the first reflector 108 is formed (see FIG. 26). Specifically, the dielectric multilayer film reflector as the first reflector 108 is formed on the central portion of the top portion of the mesa M.
In step S17, the anode electrode 109 is formed (see
In step S18, the insulating film 111 is formed (see
In step S19, a part of the insulating film 111 is removed (see
In step S20, the cathode electrode 110 is formed (see
In step S21, the support substrate 120 is attached (see
In step S22, the growth substrate 101 is removed (see
In step S23, the reflector forming substrate 130 is attached (see
In step S24, the second reflector 102 is formed on the reflector forming substrate 130 (see
In step S25, the support substrate 120 is removed (see
In step S26, an annealing treatment is performed (see
The surface emitting laser 100 according to the first embodiment of the present technology includes the first and second reflectors 108 and 102, and the resonator R including the active layer 104 and the tunnel junction layer 106 disposed between the first and second reflectors 108 and 102, and the peripheral portion of the resonator R has higher resistance than the central portion at least in the entire region in the thickness direction of the tunnel junction layer 106.
In this case, for example, in order to inject ions into the entire region in the thickness direction of the peripheral portion of the tunnel junction layer 106 when the peripheral portion of the tunnel junction layer 106 is increased in resistance by ion implantation, it is necessary to cause the ions to reach at least the boundary between the layer (for example, the first cladding layer 105) adjacent to the tunnel junction layer 106 and the tunnel junction layer 106, and a position where the ion concentration (for example, hydrogen ion concentration) becomes a peak does not exist at least in the tunnel junction layer 106.
As a result, according to the surface emitting laser 100, it is possible to provide a surface emitting laser capable of current confinement at least in the tunnel junction layer 106 while suppressing the characteristic change of the tunnel junction layer 106.
Furthermore, according to the surface emitting laser 100, it is possible to provide a surface emitting laser capable of narrowing a current at least in the tunnel junction layer 106 without performing epitaxial growth a plurality of times. As a result, it is possible to shorten the manufacturing time and reduce the manufacturing cost.
For example, according to the surface emitting laser 100, in order to generate the current confinement structure, it is not necessary to etch the tunnel junction layer to form the BTJ, and it is not necessary to perform etching and subsequent embedded regrowth, so that the number of manufacturing steps can be reduced.
According to the surface emitting laser 100, flatness on the tunnel junction layer 106 can be enhanced as compared with the case of forming the BTJ, so that it is possible to attach a semiconductor multilayer film reflector constituted by a compound semiconductor (for example, a GaAs compound semiconductor, an AlGaAs-based compound semiconductor, or the like) having high heat dissipation, for example, on the tunnel junction layer 106.
The resonator R includes the first cladding layer 105 between the tunnel junction layer 106 and the active layer 104, and in the first cladding layer 105, at least a peripheral portion of a portion on the tunnel junction layer 106 side has higher resistance than a central portion. As a result, the current can be narrowed also in the first cladding layer 105.
The first cladding layer 105 can be, for example, a p-type semiconductor layer.
The first cladding layer 105 is preferably constituted by, for example, a p-type InP compound semiconductor (for example, p-InP). In this case, this is particularly effective in a case where the surface emitting laser 100 is a long-wavelength surface emitting laser having an oscillation wavelength of 1.3 μm or more.
In the active layer 104, at least a peripheral portion of a portion on the tunnel junction layer 106 side has higher resistance than a central portion. As a result, the current can be narrowed also in the active layer 104.
The resonator R includes the second cladding layer 103 on the side opposite to the tunnel junction layer 106 side of the active layer 104, and the second cladding layer 103 has lower resistance in the central portion and the peripheral portion than in the peripheral portion of the tunnel junction layer 106. As a result, a current path can be formed in a direction including the in-plane direction of the second cladding layer 103.
The cathode electrode 110 is provided on the second cladding layer 103. As a result, the current narrowed in the current confinement region CCR and flowing in the direction including the in-plane direction of the second cladding layer 103 can flow out from the cathode electrode 110 to the outside (for example, a laser driver).
The second cladding layer 103 can be, for example, an n-type semiconductor layer.
The second cladding layer 103 is preferably constituted by, for example, an n-type InP compound semiconductor (for example, n-InP). In this case, this is particularly effective in a case where the surface emitting laser 100 is a long-wavelength surface emitting laser having an oscillation wavelength of 1.3 μm or more.
The resonator R includes the third cladding layer 107 on the side opposite to the active layer 104 side of the tunnel junction layer 106, and the third cladding layer 107 has lower resistance in the central portion and the peripheral portion than in the peripheral portion of the tunnel junction layer 106. As a result, for example, the third cladding layer 107 can function as a contact layer in contact with the electrode.
The anode electrode 109 is provided on the third cladding layer 107. As a result, the current flowing through the anode electrode 109 can efficiently flow into the third cladding layer 107.
The third cladding layer 107 can be, for example, an n-type semiconductor layer.
The third cladding layer 107 is preferably constituted by an n-type InP compound semiconductor (for example, n-InP). In this case, this is particularly effective in a case where the surface emitting laser 100 is a long-wavelength surface emitting laser having an oscillation wavelength of 1.3 μm or more.
In the resonator R, the peripheral portion is increased in resistance by ion implantation at least in the entire region in the thickness direction of the tunnel junction layer 106. As a result, it is possible to narrow the current at least in the tunnel junction layer 106 without forming the BTJ and while suppressing the characteristic change of the tunnel junction layer 106.
The impurity concentration (for example, hydrogen ion concentration) in the ion implantation is preferably less than 1×1019 cm−3. As a result, it is possible to suppress the characteristic change in each layer constituting the resonator R.
The impurity in the ion implantation preferably includes at least one of H, B, C, or O.
The substrate 130 disposed between the resonator R and the second reflector 102 that is a reflector closer to the active layer 104 than the tunnel junction layer 106 among the first and second reflectors 108 and 102 is further included, and the second reflector 102 is a concave multilayer film reflector. As a result, the second reflector 102 has both a function as a high reflectance reflector and a light confinement function.
The thermal conductivity of the substrate 130 is preferably, for example, 40 W/m·K or more. As a result, the heat dissipation of the heat generated in the resonator R can be improved.
The substrate 130 is preferably constituted by, for example, any of GaAs, Si, and SiC.
According to the surface emitting laser array including the plurality of surface emitting lasers 100, it is possible to provide the surface emitting laser array including the plurality of surface emitting lasers capable of performing current confinement at least in the tunnel junction layer 106 while suppressing the characteristic change of the tunnel junction layer 106 of each surface emitting laser 100.
The method for manufacturing the surface emitting laser 100 according to the first embodiment of the present technology includes a step of stacking the resonator R including the active layer 104 and the tunnel junction layer 106 on the growth substrate 101 (first substrate) to generate the laminate L1, and a step of implanting ions into the peripheral portion of the resonator R to make the peripheral portion higher in resistance than the central portion at least in the entire region in the thickness direction of the tunnel junction layer 106.
According to the method for manufacturing the surface emitting laser 100, it is possible to manufacture a surface emitting laser capable of performing current confinement at least in the tunnel junction layer 106 while suppressing the characteristic change of the tunnel junction layer 106.
The resonator R includes the first cladding layer 105 between the tunnel junction layer 106 and the active layer 104, and in the above step of increasing the resistance, ions are caused to reach at least a peripheral portion of a portion of the first cladding layer 105 on the tunnel junction layer 106 side, and the resistance of the peripheral portion is also increased. As a result, the surface emitting laser 100 capable of performing current confinement also in the first cladding layer 105 can be manufactured.
In the above step of increasing the resistance, ions are caused to reach at least the peripheral portion of the portion of the active layer 104 on the tunnel junction layer 106 side, and the resistance of the peripheral portion is also increased. As a result, the surface emitting laser 100 capable of performing current confinement even in the active layer 104 can be manufactured.
The resonator R includes the second cladding layer 103 on the side opposite to the tunnel junction layer 106 side of the active layer 104, and in the above step of increasing the resistance, ions are caused to reach at least a peripheral portion of a portion of the second cladding layer on the tunnel junction layer 106 side, and the resistance of the peripheral portion is also increased.
In the above step of increasing the resistance, ions are caused to reach the inside of the growth substrate 101. As a result, since the peak position of the ion concentration can be located in the growth substrate 101, the ion concentration in the resonator R can be relatively reduced, and the surface emitting laser 100 capable of suppressing the characteristic change of the resonator R can be manufactured.
The method for manufacturing the surface emitting laser 100 includes, after the above step of increasing the resistance, a step of bonding the support substrate 120 to the surface of the laminate on the resonator R side, and a step of removing the growth substrate 101 from the laminate. As a result, a portion having a peak of the ion concentration, which is highly likely to induce the characteristic change (for example, a decrease in reliability) of the element, can be excluded from the components of the surface emitting laser 100, so that it is possible to manufacture the surface emitting laser 100 capable of suppressing the characteristic change of each constituent layer.
The method for manufacturing the surface emitting laser 100 further includes a step of bonding the reflector forming substrate 130 (second substrate) to the surface of the laminate from which the growth substrate L1 has been removed, and a step of forming the second reflector 102 on the reflector forming substrate 130. As a result, for example, the surface emitting laser 100 that can form the second reflector 102 into a desired shape (for example, a concave shape) can be manufactured by processing the reflector forming substrate 130 as a base by etching or the like between the bonding step and the forming step.
The resonator R includes the third cladding layer 107 that is an n-type semiconductor layer on the side opposite to the active layer 104 side of the tunnel junction layer 106, in the step of increasing the resistance, the resistance of the peripheral portion of at least the portion of the third cladding layer 107 on the tunnel junction layer 106 side is also increased, and the method for manufacturing the surface emitting laser 100 further includes a step of reducing the resistance of the peripheral portion of at least the portion of the third cladding layer 107 on the tunnel junction layer 106 side by performing an annealing treatment on the laminate after the above step of increasing the resistance. As a result, the surface emitting laser 100 capable of causing the third cladding layer to function as a contact layer in contact with the electrode can be manufactured.
The resonator R includes the first cladding layer 105 that is a p-type semiconductor layer between the tunnel junction layer 106 and the active layer 104, and in the above step of increasing the resistance, the resistance of the peripheral portion of at least the portion of the first cladding layer 105 on the tunnel junction layer 106 side is also increased. As a result, the surface emitting laser 100 capable of narrowing the current even in the peripheral portion of the first cladding layer 105 can be manufactured.
In the above step of increasing the resistance, at least a portion of the active layer 104 on the tunnel junction layer 106 side also increases the resistance. As a result, the surface emitting laser 100 capable of narrowing the current even in the peripheral portion of the active layer 104 can be manufactured.
The resonator R includes the second cladding layer 103 that is an n-type semiconductor layer on the side opposite to the tunnel junction layer 106 side of the active layer 104, in the above step of increasing the resistance, the resistance of the peripheral portion of at least the portion of the second cladding layer 103 on the active layer 104 side is also increased, and the method for manufacturing the surface emitting laser 100 further includes a step of reducing the resistance of the peripheral portion of at least the portion of the second cladding layer 103 on the active layer 104 side by performing an annealing treatment on the laminate after the above step of increasing the resistance. As a result, it is possible to manufacture the surface emitting laser 100 in which the current path exists in the direction including the in-plane direction in the second cladding layer 103.
Hereinafter, surface emitting lasers according to Modifications 1 to 5 of the first embodiment of the present technology will be described.
As illustrated in
The surface emitting laser 100-1 can also be manufactured by the procedure of the flowchart of
At the time of manufacturing the surface emitting laser 100-1, when ion implantation is performed from the third cladding layer 107 side with respect to the peripheral portion of the laminate or the peripheral portion of the mesa formed by etching the laminate, the ion implantation energy is adjusted such that ions are implanted only in the entire region in the thickness direction of the peripheral portion of the third cladding layer 107 and the entire region in the thickness direction of the peripheral portion of the tunnel junction layer 106. As a result, the peak position of the ion concentration becomes the boundary between the tunnel junction layer 106 and the first cladding layer 105.
Therefore, only the peripheral portion of the third cladding layer 107 and the peripheral portion of the tunnel junction layer 106 are increased in resistance by ion implantation, and only the third cladding layer 107 is decreased in resistance by the subsequent annealing treatment and recovered.
According to the surface emitting laser 100-1, although the current confinement effect cannot be obtained in the first cladding layer 105 and the active layer 104, since the ion implantation depth can be made extremely shallow at the time of forming the current confinement region CCR, the width controllability of the current confinement region CCR is extremely excellent, and the manufacturing can be performed with a small number of steps, so that the productivity is high.
As illustrated in
The surface emitting laser 100-2 can also be manufactured by the procedure of the flowchart of
At the time of manufacturing the surface emitting laser 100-2, when ion implantation is performed from the third cladding layer 107 side with respect to the peripheral portion of the laminate or the peripheral portion of the mesa formed by etching the laminate, ion implantation energy is adjusted such that ions are implanted into the entire region in the thickness direction of the peripheral portion of the third cladding layer 107, the entire region in the thickness direction of the peripheral portion of the tunnel junction layer 106, and only the upper portion of the peripheral portion of the first cladding layer 105. As a result, the peak position of the ion concentration is in the first cladding layer 105.
Therefore, only the peripheral portion of the third cladding layer 107, the peripheral portion of the tunnel junction layer 106, and the upper portion of the peripheral portion of the first cladding layer 105 are increased in resistance by ion implantation, and only the third cladding layer 107 is reduced in resistance by the subsequent annealing treatment and recovered.
According to the surface emitting laser 100-2, although the current confinement effect cannot be obtained in the lower portion of the first cladding layer 105 and the active layer 104, since the ion implantation depth can be made relatively shallow at the time of forming the current confinement region CCR, the width controllability of the current confinement region CCR is excellent, and since the peak position of the ion concentration can be moved away from the tunnel junction layer 106, the characteristic change of the tunnel junction layer 106 can be further suppressed, and manufacturing can be performed with a small number of steps, so that productivity is high.
As illustrated in
The surface emitting laser 100-3 is also manufactured by the procedure of the flowchart of
At the time of manufacturing the surface emitting laser 100-3, when ion implantation is performed from the third cladding layer 107 side with respect to the peripheral portion of the laminate or the peripheral portion of the mesa formed by etching the laminate, the ion implantation energy is adjusted such that ions are implanted into the entire region in the thickness direction of the peripheral portion of the third cladding layer 107, the entire region in the thickness direction of the peripheral portion of the tunnel junction layer 106, and only the entire region in the thickness direction of the peripheral portion of the first cladding layer 105. As a result, the peak position of the ion concentration becomes a boundary between the first cladding layer 105 and the active layer 104.
Therefore, only the peripheral portion of the third cladding layer 107, the peripheral portion of the tunnel junction layer 106, and the peripheral portion of the first cladding layer 105 are increased in resistance by ion implantation, and only the third cladding layer 107 is decreased in resistance by the subsequent annealing treatment and recovered.
According to the surface emitting laser 100-3, although the current confinement effect cannot be obtained in the active layer 104, since the ion implantation depth can be made relatively shallow at the time of forming the current confinement region CCR, the width controllability of the current confinement region CCR is excellent, and since the peak position of the ion concentration can be made farther from the tunnel junction layer 106, the characteristic change of the tunnel junction layer 106 can be further suppressed, and manufacturing can be performed with a small number of steps, so that productivity is high.
As illustrated in
The surface emitting laser 100-4 is also manufactured by the procedure of the flowchart of
At the time of manufacturing the surface emitting laser 100-4, when ion implantation is performed from the third cladding layer 107 side with respect to the peripheral portion of the laminate or the peripheral portion of the mesa formed by etching the laminate, ion implantation energy is adjusted such that ions are implanted into the entire region in the thickness direction of the peripheral portion of the third cladding layer 107, the entire region in the thickness direction of the peripheral portion of the tunnel junction layer 106, the entire region in the thickness direction of the peripheral portion of the first cladding layer 105, and only the upper portion of the peripheral portion of the active layer 104. As a result, the peak position of the ion concentration is in the active layer 104.
Therefore, only the peripheral portion of the third cladding layer 107, the peripheral portion of the tunnel junction layer 106, the peripheral portion of the first cladding layer 105, and the upper portion of the peripheral portion of the active layer 104 are increased in resistance by ion implantation, and only the third cladding layer 107 is decreased in resistance and recovered by the subsequent annealing treatment.
According to the surface emitting laser 100-4, although the current confinement effect cannot be obtained in the lower portion of the active layer 104, since the ion implantation depth can be made relatively shallow at the time of forming the current confinement region CCR, the width controllability of the current confinement region CCR is excellent, and since the peak position of the ion concentration can be made further away from the tunnel junction layer 106, the characteristic change of the tunnel junction layer 106 can be further suppressed, and manufacturing can be performed with a small number of steps, so that productivity is high.
As illustrated in
The surface emitting laser 100-5 is also manufactured by the procedure of the flowchart of
At the time of manufacturing the surface emitting laser 100-5, when ions are implanted from the third cladding layer 107 side into the peripheral portion of the laminate or the peripheral portion of the mesa formed by etching the laminate, the ion implantation energy is adjusted such that ions are implanted into the entire region in the thickness direction of the peripheral portion of the third cladding layer 107, the entire region in the thickness direction of the peripheral portion of the tunnel junction layer 106, the entire region in the thickness direction of the peripheral portion of the first cladding layer 105, the entire region in the thickness direction of the peripheral portion of the active layer 104, and at least only a part in the thickness direction of the peripheral portion of the second cladding layer 103. As a result, the peak position of the ion concentration becomes the inside of the second cladding layer 103 or the boundary between the second cladding layer 103 and the growth substrate 101.
Therefore, at least only a part of the peripheral portion of the third cladding layer 107, the peripheral portion of the tunnel junction layer 106, the peripheral portion of the first cladding layer 105, the peripheral portion of the active layer 104, and the peripheral portion of the second cladding layer 103 is increased in resistance by ion implantation, and at least only a part of the peripheral portion of the third cladding layer 107 and the peripheral portion of the second cladding layer 103 in the thickness direction is decreased and recovered by the subsequent annealing treatment.
According to the surface emitting laser 100-5, since the ion implantation depth can be made slightly shallow at the time of forming the current confinement region CCR, the width controllability of the current confinement region CCR is slightly excellent, and since the peak position of the ion concentration can be further moved away from the tunnel junction layer 106, the characteristic change of the tunnel junction layer 106 can be further suppressed, and the manufacturing can be performed with a small number of steps, so that the productivity is high.
Hereinafter, a surface emitting laser 300 according to a second embodiment of the present technology will be described.
As illustrated in
More specifically, in the surface emitting laser 300, the third cladding layer 107, the tunnel junction layer 106, the first cladding layer 105, the active layer 104, and the second cladding layer 103 are arranged in this order from the substrate 130 side on the substrate 130.
In the surface emitting laser 300, the first cladding layer 105 is a p-type semiconductor layer (for example, a p-InP layer), the second cladding layer 103 is an n-type semiconductor layer (for example, an n-InP layer), and the third cladding layer 107 is an n-type semiconductor layer (for example, an n-InP layer).
In the surface emitting laser 300, the n-type semiconductor region 106b is located on the substrate 130 side (lower side) of the p-type semiconductor region 106a in the tunnel junction layer 106.
In the surface emitting laser 300, the anode electrode 109 is provided on the third cladding layer 107, and a current path exists in the third cladding layer 107, and the cathode electrode 110 is provided on the top portion of the mesa M (for example, the first cladding layer 103), and a current path exists in the second cladding layer 103.
Hereinafter, a method for manufacturing the surface emitting laser 300 will be described.
Similarly to the surface emitting laser 100, the surface emitting laser 300 is also manufactured by the procedure of the flowchart of
Hereinafter, the laminate generation process 2 will be described with reference to the flowchart (steps T3-1 to T3-6) of
In the first step T3-1, as an example, the third cladding layer 107 (for example, an n-InP layer) is grown as a first type semiconductor layer on the growth substrate 101 (for example, an InP substrate).
In the next step T3-2, the n-type semiconductor region 106b of the tunnel junction layer 106 is grown on the third cladding layer 107.
In the next step T3-3, the p-type semiconductor region 106a of the tunnel junction layer 106 is grown on the n-type semiconductor region 106b.
In the next step T3-4, the first cladding layer 105 is grown as a p-type semiconductor layer (for example, a p-InP layer) on the p-type semiconductor region 106a.
In the next step T3-5, the active layer 104 is grown on the first cladding layer 105.
In the final step T3-6, the second cladding layer 103 (for example, an n-InP layer) is grown as a second n-type semiconductor layer on the active layer 104. As a result, a laminate L3 (see
Next, ion implantation is performed such that ions reach the growth substrate 101 from the second cladding layer 103 side with respect to the peripheral portion of the laminate L3 or the peripheral portion of the mesa formed by etching the laminate L3. As a result, a peripheral portion of the second cladding layer 103, a peripheral portion of the active layer 104, a peripheral portion of the first cladding layer 105, a peripheral portion of the tunnel junction layer 106, a peripheral portion of the third cladding layer 107, and a peripheral portion of the growth substrate 101 have high resistance. Thereafter, an annealing treatment is performed, and the peripheral portion of the second cladding layer 103 which is an n-type semiconductor layer and the peripheral portion of the third cladding layer 107 which is an n-type semiconductor layer are reduced in resistance and recovered, while the peripheral portion of the tunnel junction layer 106, the peripheral portion of the active layer 104, and the peripheral portion of the first cladding layer 105 which is a p-type semiconductor layer remain increased in resistance and are not recovered.
According to the surface emitting laser 300, similar effects to those of the surface emitting laser 100 of the first embodiment can be obtained.
According to the method for manufacturing the surface emitting laser 300, similar effects to those of the method for manufacturing the surface emitting laser 100 are obtained.
Hereinafter, surface emitting lasers 300-1 to 300-4 according to Modification 1 to 4 of the second embodiment of the present technology will be described.
As illustrated in
The surface emitting laser 300-1 is manufactured by the procedure of the flowchart of
At the time of manufacturing the surface emitting laser 300-1, when ions are implanted into the peripheral portion of the laminate L3 or the peripheral portion of the mesa M formed by etching the laminate L3 from the second cladding layer 103 side, the ion implantation energy is adjusted such that ions are implanted into the entire region of the peripheral portion of the second cladding layer 103 in the thickness direction, the entire region of the peripheral portion of the active layer 104 in the thickness direction, the entire region of the peripheral portion of the first cladding layer 105 in the thickness direction, the entire region of the peripheral portion of the tunnel junction layer 106 in the thickness direction, and at least only a part of the peripheral portion of the third cladding layer 107 in the thickness direction. As a result, the peak position of the ion concentration is in the third cladding layer 107 or in the vicinity of the boundary between the third cladding layer 107 and the growth substrate 101.
Therefore, at least only a part in the thickness direction of the peripheral portion of the second cladding layer 103, the peripheral portion of the active layer 104, the peripheral portion of the first cladding layer 105, the peripheral portion of the tunnel junction layer 106, and the peripheral portion of the third cladding layer 107 is increased by ion implantation, and at least only a part in the thickness direction of the peripheral portion of the second cladding layer 103 and the peripheral portion of the third cladding layer 107 is decreased and recovered by the subsequent annealing treatment.
According to the surface emitting laser 300-1, since the ion implantation depth can be made slightly shallow at the time of forming the current confinement region CCR, the width controllability of the current confinement region CCR is slightly excellent, and since the peak position of the ion concentration can be further moved away from the tunnel junction layer 106, the characteristic change of the tunnel junction layer 106 can be further suppressed, and the manufacturing can be performed with a small number of steps, so that the productivity is high.
As illustrated in
More specifically, in the surface emitting laser 300-2, the first cladding layer 105 is a p-type semiconductor layer (for example, a p-InP layer), the second cladding layer 103 is an n-type semiconductor layer (for example, an n-InP layer), and the third cladding layer 107 is a p-type semiconductor layer (for example, a p-InP layer).
In the surface emitting laser 300-2, the anode electrode 109 is provided on the upper surface of the substrate 130 which is a conductive substrate, a current path exists in the substrate 130, and the cathode electrode 110 is provided on the top portion of the mesa M (for example, the second cladding layer 103).
Hereinafter, a method for manufacturing the surface emitting laser 300-2 will be described.
Similarly to the surface emitting laser 300, the surface emitting laser 300-2 is also manufactured by the procedure of the flowchart of
The laminate generation process 3 will be described below with reference to the flowchart (steps T4-1 to T4-6) of
In the first step T4-1, as an example, the third cladding layer 107 (for example, a p-InP layer) is grown as a first p-type semiconductor layer on the growth substrate 101 (for example, an InP substrate).
In the next step T4-2, the n-type semiconductor region 106b of the tunnel junction layer 106 is grown on the third cladding layer 107.
In the next step T4-3, the p-type semiconductor region 106a of the tunnel junction layer 106 is grown on the n-type semiconductor region 106b.
In the next step T4-4, the first cladding layer 105 (for example, a p-InP layer) is grown as a second p-type semiconductor layer on the p-type semiconductor region 106a.
In the next step T4-5, the active layer 104 is grown on the second p-type semiconductor layer.
In the final step T4-6, the second cladding layer 103 (for example, an n-InP layer) is grown as an n-type semiconductor layer on the active layer 104. As a result, a laminate L4 (see
Next, ion implantation is performed such that ions reach the growth substrate 101 from the second cladding layer 103 side with respect to the peripheral portion of the laminate L4 or the peripheral portion of the mesa formed by etching the laminate L4. As a result, a peripheral portion of the second cladding layer 103, a peripheral portion of the active layer 104, a peripheral portion of the first cladding layer 105, a peripheral portion of the tunnel junction layer 106, a peripheral portion of the third cladding layer 107, and a peripheral portion of the growth substrate 101 have high resistance. Thereafter, an annealing treatment is performed, and only the peripheral portion of the second cladding layer 103 which is an n-type semiconductor layer is reduced in resistance and recovered, while the peripheral portion of the active layer 104, the peripheral portion of the first cladding layer 105, the peripheral portion of the tunnel junction layer 106, and the peripheral portion of the third cladding layer 107 remain high in resistance and are not recovered.
According to the surface emitting laser 300-2, similar effects to those of the surface emitting laser 300 of the second embodiment can be obtained.
According to the method for manufacturing the surface emitting laser 300-2, similar effects to those of the method for manufacturing the surface emitting laser 300 are obtained.
As illustrated in
Hereinafter, a method for manufacturing the surface emitting laser 300-3 will be briefly described.
The surface emitting laser 300-3 is also manufactured by the procedure of the flowchart of
In the method for manufacturing the surface emitting laser 300-3, first, a laminate generation process 4 as an example of the laminate generation process is performed. Next, ion implantation is performed so that ions reach the third cladding layer 107 from the second cladding layer 103 side with respect to the peripheral portion of the laminate L4 generated in the laminate generation process 4 or the peripheral portion of the mesa M formed by etching the laminate L4. As a result, a peripheral portion of the second cladding layer 103, a peripheral portion of the active layer 104, a peripheral portion of the first cladding layer 105, a peripheral portion of the tunnel junction layer 106, and an upper portion of a peripheral portion of the third cladding layer 107 (a portion on the tunnel junction layer 106 side) have high resistance. Thereafter, an annealing treatment is performed, and the peripheral portion of the second cladding layer 103 is recovered by reducing the resistance, while the peripheral portion of the active layer 104, the peripheral portion of the first cladding layer 105, the peripheral portion of the tunnel junction layer 106, and the upper portion of the peripheral portion of the third cladding layer 107 remain high in resistance and are not recovered.
According to the surface emitting laser 300-3, although the current confinement effect cannot be obtained in the lower portion of the peripheral portion of the third cladding layer 107, since the ion implantation depth can be made slightly shallow at the time of forming the current confinement region CCR, the width controllability of the current confinement region CCR is slightly excellent, and manufacturing can be performed with a small number of steps, so that productivity is high.
As illustrated in
The surface emitting laser 300-4 is manufactured by the procedure of the flowchart of
The surface emitting laser 300-4 has similar effects to those of the surface emitting laser 300-2.
Hereinafter, a surface emitting laser 400 according to a third embodiment of the present technology will be described.
As illustrated in
In the surface emitting laser 400, for example, the cathode electrode 110 is provided in a frame shape (for example, an annular shape) on the back surface (lower surface) of the conductive substrate 130 so as to surround the second reflector 102.
Hereinafter, a method for manufacturing the surface emitting laser 400 will be described.
The surface emitting laser 400 is manufactured by the procedure of the flowchart (steps S61 to S75) of
In the method for manufacturing the surface emitting laser 400, in step S61, the laminate generation process 1 as an example of the laminate generation process is performed.
Next, ion implantation is performed so that ions reach the growth substrate 101 from the third cladding layer 107 side with respect to the peripheral portion of the laminate L1. As a result, a peripheral portion of the third cladding layer 107, a peripheral portion of the tunnel junction layer 106, a peripheral portion of the first cladding layer 105, a peripheral portion of the active layer 104, a peripheral portion of the second cladding layer 103, and a peripheral portion of the growth substrate 101 have high resistance. Thereafter, an annealing treatment is performed, and the peripheral portion of the third cladding layer 107 which is an n-type semiconductor layer and the peripheral portion of the second cladding layer 103 which is an n-type semiconductor layer are reduced in resistance and recovered, while the peripheral portion of the tunnel junction layer 106, the peripheral portion of the first cladding layer 105 which is a p-type semiconductor layer, and the peripheral portion of the active layer 104 remain increased in resistance and are not recovered.
According to the surface emitting laser 400, similar effects to those of the surface emitting laser 100 of the first embodiment can be obtained.
According to the method for manufacturing the surface emitting laser 400, effects similar to those of the method for manufacturing the surface emitting laser 100 are obtained, and since the mesa M is not formed, manufacturing can be performed with a small number of steps, and productivity is high.
Note that, in step S61 of the flowchart of
The present technology is not limited to each of the embodiments and modifications described above, and various modifications can be made.
For example, in each of the above embodiments and modifications, the cladding layer constituted by an InP-based compound semiconductor has been described as an example, but instead of this, the cladding layer may be constituted by, for example, a GaAs compound semiconductor, an AlGaAs-based compound semiconductor, or the like.
For example, each of the p-type semiconductor region 106a and the n-type semiconductor region 106b may be constituted by, for example, any of an InP-based compound semiconductor, an AlGaInAs-based compound semiconductor, and an AlGaInSbAs-based compound semiconductor.
Each of the first and second reflectors 108 and 102 may be a semiconductor multilayer film reflector constituted by a compound of two or more elements of Al, Ga, and As.
Some of the configurations of the surface emitting laser of each of the above embodiments and modifications may be combined within a range in which they do not contradict each other.
In each of the embodiments and modifications described above, the material, conductivity type, thickness, width, length, shape, size, arrangement, and the like of each component constituting the surface emitting laser can be appropriately changed within a range functioning as the surface emitting laser.
The technology according to the present disclosure (the present technology) can be applied to various products (electronic devices). For example, the technology according to the present disclosure may be implemented as a device mounted on any type of mobile body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a ship, and a robot.
The surface emitting laser according to the present technology can also be applied as, for example, a light source of a device that forms or displays an image by laser light (for example, a laser printer, a laser copier, a projector, a head-mounted display, a head-up display, or the like).
Hereinafter, application examples of the surface emitting laser according to each of the embodiments and modifications described above will be described.
The light receiving device 125 detects light reflected by the subject S. The lens 115 is a lens for collimating the light emitted from the surface emitting laser 100, and is a collimating lens. The lens 135 is a lens for condensing light reflected by the subject S and guiding the light to the light receiving device 125, and is a condenser lens.
The signal processing section 140 is a circuit for generating a signal corresponding to a difference between a signal input from the light receiving device 125 and a reference signal input from the control section 150. The control section 150 includes, for example, a time to digital converter (TDC). The reference signal may be a signal input from the control section 150, or may be an output signal of a detecting section that directly detects the output of the surface emitting laser 100. The control section 150 is, for example, a processor that controls the surface emitting laser 100, the light receiving device 125, the signal processing section 140, the display section 160, and the storage section 170. The control section 150 is a circuit that measures a distance to the subject S on the basis of a signal generated by the signal processing section 140. The control section 150 generates a video signal for displaying information about the distance to the subject S, and outputs the video signal to the display section 160. The display section 160 displays information about the distance to the subject S on the basis of the video signal input from the control section 150. The control section 150 stores information about the distance to the subject S in the storage section 170.
In the present application example, instead of the surface emitting laser 100, any one of the above surface emitting lasers 100-1 to 100-5, 200, 200-1 to 200-5, 300, 300-1 to 300-4, and 400 can be applied to the distance measuring device 1000.
A vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. In the example illustrated in
The driving system control unit 12010 controls an operation of devices related to a drive system of a vehicle in accordance with various programs. For example, the driving system control unit 12010 functions as a control device for a driving force generating device for generating the driving force of the vehicle, such as an internal combustion engine, a driving motor, or the like, a driving force transmitting mechanism for transmitting the driving force to wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating the braking force of the vehicle, and the like.
The body system control unit 12020 controls an operation of various devices mounted on a vehicle body in accordance with various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various kinds of lamps such as a headlamp, a backup lamp, a brake lamp, a turn signal, or a fog lamp. In this case, radio waves transmitted from a mobile device as an alternative to a key or signals of various kinds of switches can be input to the body system control unit 12020. The body system control unit 12020 receives an input of these radio waves or signals, and controls a door lock device, a power window device, a lamp, and the like of the vehicle.
The outside-vehicle information detecting unit 12030 detects information about the outside of the vehicle including the vehicle control system 12000. For example, a distance measuring device 12031 is connected to the outside-vehicle information detecting unit 12030. The distance measuring device 12031 includes the above-described distance measuring device 1000. The outside-vehicle information detecting unit 12030 causes the distance measuring device 12031 to measure a distance to an object (subject S) outside the vehicle, and acquires distance data obtained by the measurement. The outside-vehicle information detecting unit 12030 may perform object detection processing of a person, a vehicle, an obstacle, a sign, or the like on the basis of the acquired distance data.
The in-vehicle information detecting unit 12040 detects information about the inside of the vehicle. For example, a driver state detecting section 12041 for detecting the state of a driver is connected to the in-vehicle information detecting unit 12040. The driver state detecting section 12041, for example, includes a camera that images the driver. On the basis of detection information input from the driver state detecting section 12041, the in-vehicle information detecting unit 12040 may calculate the degree of fatigue of the driver or the degree of concentration of the driver or may determine whether the driver is awake.
The microcomputer 12051 can calculate a control target value for the driving force generating device, the steering mechanism, or the braking device on the basis of the information about the inside or outside of the vehicle which information is obtained by the outside-vehicle information detecting unit 12030 or the in-vehicle information detecting unit 12040, and output a control command to the driving system control unit 12010. For example, the microcomputer 12051 can perform cooperative control intended to implement functions of an advanced driver assistance system (ADAS) which functions include collision avoidance or shock mitigation for the vehicle, following driving based on a following distance, vehicle speed maintaining driving, a warning of collision of the vehicle, a lane deviation warning of the vehicle, or the like.
In addition, the microcomputer 12051 can perform cooperative control intended for automated driving, which makes the vehicle to travel automatedly without depending on the operation of the driver, or the like, by controlling the driving force generating device, the steering mechanism, the braking device, or the like on the basis of the information about the outside or inside of the vehicle which information is obtained by the outside-vehicle information detecting unit 12030 or the in-vehicle information detecting unit 12040.
In addition, the microcomputer 12051 can output a control command to the body system control unit 12020 on the basis of the information about the outside of the vehicle acquired by the outside-vehicle information detecting unit 12030. For example, the microcomputer 12051 can perform cooperative control intended to prevent glare by controlling the headlamp so as to switch from a high beam to a low beam or the like, for example, according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detecting unit 12030.
The sound/image output section 12052 transmits an output signal of at least one of a sound or an image to an output device capable of visually or auditorily notifying an occupant of the vehicle or the outside of the vehicle of information. In the example in
In
The distance measuring devices 12101, 12102, 12103, 12104, and 12105 are provided at positions such as, for example, a front nose, sideview mirrors, a rear bumper, a back door, and an upper portion of a windshield in a vehicle cabin, of the vehicle 12100. The distance measuring device 12101 provided on the front nose and the distance measuring device 12105 provided on the upper portion of the windshield in the vehicle cabin mainly acquire data of the front side of the vehicle 12100. The distance measuring devices 12102 and 12103 provided at the sideview mirrors mainly acquire data on the sides of the vehicle 12100. The distance measuring device 12104 provided on the rear bumper or the back door mainly acquires data behind the vehicle 12100. The data of the front side acquired by the distance measuring devices 12101 and 12105 is mainly used for detecting a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, or the like.
Note that
For example, the microcomputer 12051 can determine a distance to each three-dimensional object within the detection ranges 12111 to 12114 and a temporal change in the distance (a relative speed with respect to the vehicle 12100) on the basis of the distance data obtained from the distance measuring devices 12101 to 12104, and thereby extract, as a preceding vehicle, a nearest three-dimensional object in particular that is present on a traveling path of the vehicle 12100 and which travels in substantially the same direction as the vehicle 12100 at a predetermined speed (for example, equal to or more than 0 km/hour). Moreover, the microcomputer 12051 can set a following distance to be maintained in front of a preceding vehicle in advance, and perform automatic brake control (including following stop control), automatic acceleration control (including following start control), or the like. It is thus possible to perform cooperative control intended for automated driving, in which the vehicle travels automatedly without depending on the operation of the driver or the like.
For example, the microcomputer 12051 can classify three-dimensional object data on three-dimensional objects into three-dimensional object data of a two-wheeled vehicle, a standard-sized vehicle, a large-sized vehicle, a pedestrian, a utility pole, and the like, and other three-dimensional objects on the basis of the distance data obtained from the distance measuring devices 12101 to 12104, extract the classified three-dimensional object data, and use the extracted three-dimensional object data for automatic avoidance of an obstacle. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that the driver of the vehicle 12100 can recognize visually and obstacles that are difficult for the driver of the vehicle 12100 to recognize visually. Then, the microcomputer 12051 determines a collision risk indicating a risk of collision with each obstacle. In a situation in which the collision risk is higher than or equal to a set value and there is thus a possibility of collision, the microcomputer 12051 can outputs a warning to the driver via the audio speaker 12061 or the display section 12062 and perform forced deceleration or avoidance steering via the driving system control unit 12010 to perform driving assistance for collision avoidance.
An example of the mobile body control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the distance measuring device 12031 among the configurations described above.
Furthermore, the present technology can also have the following configurations.
(1) A surface emitting laser including:
(2) The surface emitting laser according to (1), in which the resonator includes a cladding layer between the tunnel junction layer and the active layer, and in the cladding layer, at least a peripheral portion of a portion on a side of the tunnel junction layer has higher resistance than a central portion.
(3) The surface emitting laser according to (1) or (2), in which the cladding layer is a p-type semiconductor layer.
(4) The surface emitting laser according to (2) or (3), in which the cladding layer is constituted by a p-type InP compound semiconductor.
(5) The surface emitting laser according to any one of (1) to (4), in which in the active layer, at least a peripheral portion of a portion on a side of the tunnel junction layer has higher resistance than a central portion.
(6) The surface emitting laser according to any one of (1) to (5), in which the resonator includes another cladding layer on a side of the active layer opposite to a side of the tunnel junction layer, and in the another cladding layer, a central portion and a peripheral portion have lower resistance than a peripheral portion of the tunnel junction layer.
(7) The surface emitting laser according to (6), in which an electrode is provided on the another cladding layer.
(8) The surface emitting laser according to (6) or (7), in which the another cladding layer is an n-type semiconductor layer.
(9) The surface emitting laser according to any one of (6) to (8), in which the another cladding layer is constituted by an n-type InP compound semiconductor.
(10) The surface emitting laser according to any one of (1) to (9), in which the resonator includes further another cladding layer on a side of the tunnel junction layer opposite to a side of the active layer, and in the further another cladding layer, a central portion and a peripheral portion have lower resistance than a peripheral portion of the tunnel junction layer.
(11) The surface emitting laser according to (10), in which an electrode is provided on the further another cladding layer.
(12) The surface emitting laser according to (10) or (11), in which the further another cladding layer is an n-type semiconductor layer.
(13) The surface emitting laser according to any one of (10) to (12), in which the cladding layer is constituted by an n-type InP compound semiconductor.
(14) The surface emitting laser according to any one of (1) to (13), in which a peripheral portion of the resonator is increased in resistance by ion implantation at least in an entire region in a thickness direction of the tunnel junction layer.
(15) The surface emitting laser according to (14), in which an impurity concentration in the ion implantation is less than 1 1019 cm−3. (16) The surface emitting laser according to (14) or (15), in which impurity in the ion implantation includes at least one of H, B, C, or O.
(17) The surface emitting laser according to any one of (1) to (16), in which the tunnel junction layer includes a p-type semiconductor region and an n-type semiconductor region, and each of the p-type semiconductor region and the n-type semiconductor region is constituted by any of an InP-based compound semiconductor, an AlGaInAs-based compound semiconductor, and an AlGaInSbAs-based compound semiconductor.
(18) The surface emitting laser according to any one of (1) to (17), further including a substrate disposed between the resonator and a reflector closer to the active layer than the tunnel junction layer among the first and second reflectors, in which the reflector is a concave multilayer film reflector.
(19) The surface emitting laser according to (18), in which a thermal conductivity of the substrate is 40 W/m·K or more.
(20) The surface emitting laser according to (18) or (19), in which the substrate is constituted by any of GaAs, Si, and SiC.
(21) The surface emitting laser according to any one of (18) to (20), in which the reflector is a semiconductor multilayer film reflector constituted by a compound of two or more elements of Al, Ga, and As.
(22) A surface emitting laser array including a plurality of the surface emitting laser according to any one of (1) to (21).
(23) An electronic device including the surface emitting laser according to any one of (1) to (21).
(24) An electronic device including the surface emitting laser array according to (22).
(25) A method for manufacturing a surface emitting laser, the method including:
(26) The method for manufacturing a surface emitting laser according to (25), in which the resonator includes a cladding layer between the tunnel junction layer and the active layer, and in the step of increasing the resistance, resistance of a peripheral portion of at least a portion of the cladding layer on a side of the tunnel junction layer is also increased.
(27) The method for manufacturing a surface emitting laser according to (25) or (26), in which, in the step of increasing the resistance, resistance of a peripheral portion of at least a portion of the active layer on a side of the tunnel junction layer is also increased.
(28) The surface emitting laser according to any one of (25) to (27), in which the resonator includes a cladding layer on a side of the active layer opposite to a side of the tunnel junction layer, and in the step of increasing the resistance, resistance of a peripheral portion of at least a portion of the cladding layer on a side of the tunnel junction layer is also increased.
(29) The method for manufacturing a surface emitting laser according to any one of (25) to (28), in which ions are caused to reach the first substrate in the step of increasing the resistance.
(30) The method for manufacturing a surface emitting laser according to any one of (25) to (29), further including: after the step of increasing the resistance, a step of bonding a support substrate to a surface of the laminate on a side of the resonator; and a step of removing the first substrate from the laminate.
(31) The method for manufacturing a surface emitting laser according to (30), further including: a step of bonding a second substrate to a surface of the laminate from which the first substrate has been removed; and a step of forming a reflector on the second substrate.
(32) The method for manufacturing a surface emitting laser according to any one of (25) to (31), in which the resonator includes an n-type semiconductor layer on a side of the tunnel junction layer opposite to a side of the active layer, and in the step of increasing the resistance, resistance of a peripheral portion of at least a portion of the n-type semiconductor layer on a side of the tunnel junction layer is also increased.
(33) The method for manufacturing a surface emitting laser according to (32), further including, after the step of increasing the resistance, a step of performing an annealing treatment on the laminate to reduce resistance of at least a peripheral portion of a portion of the n-type semiconductor layer on a side of the tunnel junction layer.
(34) The method for manufacturing a surface emitting laser according to any one of (25) to (33), in which the resonator includes a p-type semiconductor layer on a side of the tunnel junction layer opposite to a side of the active layer, and in the step of increasing the resistance, resistance of a peripheral portion of at least a portion of the p-type semiconductor layer on a side of the tunnel junction layer is also increased.
(35) The method for manufacturing a surface emitting laser according to any one of (25) to (34), in which the resonator includes a p-type semiconductor layer between the tunnel junction layer and the active layer, and in the step of increasing the resistance, resistance of a peripheral portion of at least a portion of the p-type semiconductor layer on a side of the tunnel junction layer is also increased.
(36) The method for manufacturing a surface emitting laser according to any one of (25) to (35), in which the resonator includes an n-type semiconductor layer between the tunnel junction layer and the active layer, and in the step of increasing the resistance, resistance of a peripheral portion of at least a portion of the n-type semiconductor layer on a side of the tunnel junction layer is also increased.
(37) The method for manufacturing a surface emitting laser according to (36), further including, after the step of increasing the resistance, a step of performing an annealing treatment on the laminate to reduce resistance of at least a peripheral portion of a portion of the n-type semiconductor layer on a side of the tunnel junction layer.
(38) The method for manufacturing a surface emitting laser according to any one of (25) to (37), in which the resonator includes an n-type semiconductor layer on a side of the active layer opposite to a side of the tunnel junction layer, and in the step of increasing the resistance, resistance of a peripheral portion of at least a portion of the n-type semiconductor layer on a side of the active layer is also increased.
(39) The method for manufacturing a surface emitting laser according to (38), further including, after the step of increasing the resistance, a step of performing an annealing treatment on the laminate to reduce resistance of at least a peripheral portion of a portion of the n-type semiconductor layer on a side of the active layer.
(40) The method for manufacturing a surface emitting laser according to any one of (25) to (39), in which the resonator includes a p-type semiconductor layer on a side of the active layer opposite to a side of the tunnel junction layer, and in the step of increasing the resistance, resistance of a peripheral portion of at least a portion of the p-type semiconductor layer on a side of the active layer is also increased.
(41) The surface emitting laser according to (1), in which the resonator includes a cladding layer between the tunnel junction layer and the active layer, and in the cladding layer, a central portion and a peripheral portion have lower resistance than a peripheral portion of the tunnel junction layer.
(42) The surface emitting laser according to (41), in which the cladding layer is an n-type semiconductor layer.
(43) The surface emitting laser according to (41) or (42), in which the cladding layer is constituted by an n-type InP compound semiconductor.
(44) The surface emitting laser according to any one of (41) to (43), in which in the active layer, at least a peripheral portion of a portion on a side of the tunnel junction layer has higher resistance than a central portion.
(45) The surface emitting laser according to any one of (41) to (44), in which the resonator includes another cladding layer on a side of the active layer opposite to a side of the tunnel junction layer, and in the another cladding layer, at least a peripheral portion of a portion on a side of the tunnel junction layer has higher resistance than a central portion.
(46) The surface emitting laser according to (45), in which an electrode is provided on the another cladding layer or a substrate disposed on a side of the another cladding layer opposite to a side of the tunnel junction layer.
(47) The surface emitting laser according to (45) or (46), in which the another cladding layer is a p-type semiconductor layer.
(48) The surface emitting laser according to any one of (45) to (47), in which the another cladding layer is constituted by a p-type InP compound semiconductor.
(49) The surface emitting laser according to any one of (41) to (48), in which the resonator includes further another cladding layer on a side of the tunnel junction layer opposite to a side of the active layer, and in the further another cladding layer, a central portion and a peripheral portion have lower resistance than a peripheral portion of the tunnel junction layer.
(50) The surface emitting laser according to (49), in which an electrode is provided on the further another cladding layer.
(51) The surface emitting laser according to (49) or (50), in which the further another cladding layer is an n-type semiconductor layer.
(52) The surface emitting laser according to any one of (49) to (51), in which the further another cladding layer is constituted by an n-type InP compound semiconductor.
(53) The surface emitting laser according to (1), in which the resonator includes a cladding layer between the tunnel junction layer and the active layer, and in the cladding layer, at least a peripheral portion of a portion on a side of the tunnel junction layer has higher resistance than a central portion.
(54) The surface emitting laser according to (53), in which the cladding layer is a p-type semiconductor layer.
(55) The surface emitting laser according to (53) or (54), in which the cladding layer is constituted by a p-type InP compound semiconductor.
(56) The surface emitting laser according to any one of (53) to (55), in which in the active layer, at least a peripheral portion of a portion on a side of the tunnel junction layer has higher resistance than a central portion.
(57) The surface emitting laser according to any one of (53) to (56), in which the resonator includes another cladding layer on a side of the active layer opposite to a side of the tunnel junction layer, and in the another cladding layer, a central portion and a peripheral portion have lower resistance than a peripheral portion of the tunnel junction layer.
(58) The surface emitting laser according to (57), in which an electrode is provided on the another cladding layer.
(59) The surface emitting laser according to (57) or (58), in which the another cladding layer is an n-type semiconductor layer.
(60) The surface emitting laser according to any one of (57) to (59), in which the another cladding layer is constituted by an n-type InP compound semiconductor.
(61) The surface emitting laser according to any one of (53) to (60), in which the resonator includes further another cladding layer on a side of the tunnel junction layer opposite to a side of the active layer, and in the further another cladding layer, at least a peripheral portion of a portion on a side of the tunnel junction layer has higher resistance than a (62) The surface emitting laser according to (61), in which an electrode is provided on the further another cladding layer or a substrate disposed on a side of the further another cladding layer opposite to a side of the tunnel junction layer.
(63) The surface emitting laser according to (61) or (62), in which the further another cladding layer is a p-type semiconductor layer.
(64) The surface emitting laser according to any one of (61) to (63), in which the further another cladding layer is constituted by a p-type InP compound semiconductor.
(65) A surface emitting laser including:
(66) The surface emitting laser according to (65), in which the cladding layer is a p-type semiconductor layer, and each of the another cladding layer and the further another cladding layer is an n-type semiconductor layer.
(67) The surface emitting laser according to (65), in which each of the cladding layer and the further another cladding layer is an n-type semiconductor layer, and the another cladding layer is a p-type semiconductor layer.
(68) The surface emitting laser according to (65),
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-033502 | Mar 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/002086 | 1/21/2022 | WO |
