The present disclosure relates to a solid-state imaging element and an electronic device.
In recent years, in a back irradiation type complementary metal oxide semiconductor (CMOS) image sensor, there is a technique of causing light to be incident on a pair of photodiodes from the same on-chip lens to detect a phase difference (see, for example, Patent Literature 1).
However, in the above-described conventional technique, by causing light to be incident on the pair of photodiodes from the same on-chip lens, the incident light may be largely scattered in a separation region disposed between the pair of photodiodes, and non-uniform color mixing may occur.
Therefore, the present disclosure proposes a solid-state imaging element and an electronic device capable of improving non-uniformity of color mixing.
According to the present disclosure, there is provided a solid-state imaging element. The solid-state imaging element includes a plurality of light-receiving pixels arranged in a matrix inside a semiconductor layer. The light-receiving pixel includes a pair of photoelectric conversion units, a first separation region, a second separation region, and a third separation region. The pair of photoelectric conversion units are disposed adjacent to each other. The first separation region is disposed so as to surround the pair of photoelectric conversion units and is disposed so as to penetrate the semiconductor layer. The second separation region is disposed between the pair of photoelectric conversion units and is disposed so as to penetrate the semiconductor layer. The third separation region is disposed in a region surrounded by the first separation region and is disposed from a light incident surface of the semiconductor layer to a middle of the semiconductor layer.
Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that in the following embodiments, the same portion is denoted by the same reference numeral, and redundant description will be omitted.
In recent years, in a back irradiation type complementary metal oxide semiconductor (CMOS) image sensor, there is a technique of causing light to be incident on a pair of photodiodes from the same on-chip lens to detect a phase difference.
However, in the above-described conventional technique, by causing light to be incident on the pair of photodiodes from the same on-chip lens, the incident light may be largely scattered in a separation region disposed between the pair of photodiodes. Then, the largely scattered light is incident on another photodiode, and color mixing may thereby occur in the pixel array unit.
In addition, occurrence of such color mixing is particularly significant in another photodiode adjacent in a direction perpendicular to a direction in which the separation region extends. That is, in the above-described conventional technique, color mixing may occur non-uniformly in a plurality of photodiodes disposed around the pair of photodiodes.
Therefore, implementation of a technique capable of overcoming the above-described problems and improving non-uniformity of color mixing is expected.
The pixel array unit 10, the system control unit 12, the vertical drive unit 13, the column read circuit unit 14, the column signal processing unit 15, the horizontal drive unit 16, and the signal processing unit 17 are disposed on the same semiconductor substrate or on a plurality of electrically connected laminated semiconductor substrates.
In the pixel array unit 10, light-receiving pixels 11 each having a photoelectric conversion element (photodiode 21 (see
In addition, in addition to the light-receiving pixels 11, the pixel array unit 10 may include a region in which a dummy pixel not including the photodiode 21, a light-shielding pixel in which incidence of light coming from the outside is blocked by shielding a light-receiving surface from light, and the like are arranged in a row and/or a column. Note that the light-shielding pixel may have a configuration similar to the light-receiving pixel 11 except that the light-shielding pixel has a light-receiving surface shielded from light. In addition, hereinafter, a photocharge of a charge amount corresponding to the amount of incident light is also simply referred to as “charge”, and the light-receiving pixel 11 may also be simply referred to as “pixel”.
In the pixel array unit 10, for the pixel array in a matrix, a pixel drive line LD is formed for each row in the left-right direction in the drawing (pixel array direction in a pixel row), and a vertical pixel line LV is formed for each column in the up-down direction in the drawing (pixel array direction in a pixel column). One end of the pixel drive line LD is connected to an output terminal corresponding to each row of the vertical drive unit 13.
The column read circuit unit 14 includes at least a circuit that supplies a constant current to the light-receiving pixels 11 in a selected row in the pixel array unit 10 for each column, a current mirror circuit, a changeover switch of the light-receiving pixel 11 to be read, and the like.
The column read circuit unit 14 constitutes an amplifier together with a transistor in a selected pixel in the pixel array unit 10, converts a photocharge signal into a voltage signal, and outputs the voltage signal to the vertical pixel line LV.
The vertical drive unit 13 includes a shift register, an address decoder, and the like, and drives the light-receiving pixels 11 of the pixel array unit 10, for example, at the same time for all the pixels or row by row. Although a specific configuration of the vertical drive unit 13 is not illustrated, the vertical drive unit 13 has a configuration including a read scanning system and a sweep scanning system or a batch sweep and a batch transfer system.
The read scanning system sequentially selects and scans the light-receiving pixels 11 of the pixel array unit 10 row by row in order to read a pixel signal from the light-receiving pixels 11. In a case of row driving (rolling shutter operation), as for sweep, sweep scanning is performed on a read row on which read scanning is performed by the read scanning system prior to the read scanning by a time corresponding to a shutter speed.
In addition, in a case of global exposure (global shutter operation), batch sweep is performed prior to batch transfer by a time corresponding to a shutter speed. By such sweep, unnecessary charges are swept (reset) from the photodiodes 21 of the light-receiving pixels 11 in the read row. Then, a so-called electronic shutter operation is performed by sweeping (resetting) unnecessary charges.
Here, the electronic shutter operation refers to an operation of discarding unnecessary photocharges accumulated in the photodiode 21 until immediately before and newly starting exposure (starting accumulation of photocharges).
A signal read by the read operation performed by the read scanning system corresponds to the amount of light incident after the immediately preceding read operation or the electronic shutter operation. In the case of row driving, a period from a read timing by the immediately preceding read operation or a sweep timing by the electronic shutter operation to a read timing by the current read operation is a photocharge accumulation time (exposure time) in the light-receiving pixel 11. In the case of global exposure, a period from batch sweep to batch transfer is the accumulation time (exposure time).
The pixel signal output from each of the light-receiving pixels 11 in the pixel row selected and scanned by the vertical drive unit 13 is supplied to the column signal processing unit 15 through each of the vertical pixel lines LV. The column signal processing unit 15 performs predetermined signal processing on the pixel signal output from each of the light-receiving pixels 11 in the selected row through the vertical pixel line LV for each pixel column of the pixel array unit 10, and temporarily holds the pixel signal after the signal processing.
Specifically, the column signal processing unit 15 performs at least noise removal processing, for example, correlated double sampling (CDS) processing as the signal processing. By the CDS processing performed by the column signal processing unit 15, fixed pattern noise unique to pixels, such as reset noise or threshold variation of an amplification transistor AMP is removed.
Note that the column signal processing unit 15 can be configured to have, for example, an AD conversion function in addition to the noise removal processing and to output the pixel signal as a digital signal.
The horizontal drive unit 16 includes a shift register, an address decoder, and the like, and sequentially selects a unit circuit corresponding to a pixel column of the column signal processing unit 15. By selection and scanning performed by the horizontal drive unit 16, the pixel signals that have been subjected to the signal processing by the column signal processing unit 15 are sequentially output to the signal processing unit 17.
The system control unit 12 includes a timing generator that generates various timing signals, and the like, and performs drive control of the vertical drive unit 13, the column signal processing unit 15, the horizontal drive unit 16, and the like on the basis of various timing signals generated by the timing generator.
The solid-state imaging element 1 further includes the signal processing unit 17 and a data storage unit (not illustrated). The signal processing unit 17 has at least an addition processing function, and performs various types of signal processing such as addition processing on a pixel signal output from the column signal processing unit 15.
The data storage unit temporarily stores data necessary for signal processing in the signal processing unit 17. The signal processing unit 17 and the data storage unit may be processing performed by an external signal processing unit disposed on a substrate different from a substrate where the solid-state imaging element 1 is disposed, for example, a digital signal processor (DSP) or software, or may be mounted on the same substrate as the substrate where the solid-state imaging element 1 is disposed.
Next, a detailed configuration of the pixel array unit 10 according to the first embodiment will be described with reference to
As illustrated in
The semiconductor layer 20 contains, for example, silicon. The semiconductor layer 20 includes a plurality of photodiodes (PD) 21. The photodiode 21 is an example of a photoelectric conversion unit. Note that one light-receiving pixel 11 includes a pair of photodiodes 21 (hereinafter, also referred to as photodiodes 21L and 21R). In addition, the light-receiving pixel 11 has a substantially square shape in plan view, and the photodiode 21 has a substantially rectangular shape in plan view.
The photodiode 21 includes a first impurity region 22 containing a first conductivity type (for example, N type) impurity and a second impurity region 23 containing a second conductivity type (for example, P type) impurity.
The first impurity region 22 is disposed in a central portion of the photodiode 21, and the second impurity region 23 is disposed along a side portion and a bottom portion (a portion on a side opposite to a side on which light L is incident) of the first impurity region 22.
In addition, the light-receiving pixel 11 includes a first separation region 24, a second separation region 25, and a third separation region 26. As illustrated in
In addition, as illustrated in
As illustrated in
The second separation region 25 is made of, for example, a dielectric having a low refractive index, such as silicon oxide. As a result, the second separation region 25 can optically and electrically separate the plurality of photodiodes 21 adjacent to each other.
As described above, in the first embodiment, since the pair of photodiodes 21 can be separated from each other using the second separation region 25, a phase difference of incident light L can be detected using the pair of photodiodes 21.
Meanwhile, by the second separation region 25 being disposed in the light-receiving pixel 11, light L incident on an end portion on a light incident side in the second separation region 25 is largely scattered by a large refractive index difference from the photodiode 21. Then, the largely scattered light L is incident on another light-receiving pixel 11, and color mixing may thereby occur in the pixel array unit 10.
In addition, occurrence of such color mixing is particularly significant in another light-receiving pixel 11 adjacent in a direction (left-right direction in
Therefore, in the first embodiment, the non-uniformity of color mixing in the pixel array unit 10 is improved by disposing the third separation region 26 in the light-receiving pixel 11.
Specifically, as illustrated in
In addition, as illustrated in
By disposing such a third separation region 26 in the light-receiving pixel 11, light L can be scattered also in a direction different from the second separation region 25. Therefore, according to the first embodiment, the non-uniformity of color mixing in the pixel array unit 10 can be improved.
In addition, in the first embodiment, the third separation region 26 is preferably disposed so as to straddle the second separation region 25 in plan view. As a result, since a large amount of light L can be scattered in a direction different from the second separation region 25 in plan view, the non-uniformity of color mixing in the pixel array unit 10 can be further improved.
In addition, in the first embodiment, the third separation region 26 is preferably made of the same material (for example, silicon oxide) as that of the first separation region 24 and the second separation region 25. As a result, in a process of manufacturing the light-receiving pixel 11 described later, the third separation region 26 can be formed in the same step as the first separation region 24 and the second separation region 25.
Therefore, according to the first embodiment, since the process of manufacturing the pixel array unit 10 can be simplified, cost of manufacturing the solid-state imaging element 1 can be reduced.
Meanwhile, in the first embodiment, the third separation region 26 may be made of a material different from that of the first separation region 24 and the second separation region 25. For example, the third separation region 26 may be made of a material (for example, tantalum oxide (Ta2O5) or titanium oxide (TiO2)) having a higher refractive index than that of the first separation region 24 and the second separation region 25.
As a result, since the degree of scattering of light L by the third separation region 26 can be variously controlled, the non-uniformity of color mixing in the pixel array unit 10 can be improved.
In addition, in the first embodiment, the third separation region 26 is preferably disposed so as not to penetrate the semiconductor layer 20. This can suppress the volume of the photodiode 21 from being reduced by the third separation region 26.
Therefore, according to the first embodiment, it is possible to suppress a saturation signal charge amount of the photodiode 21 from being reduced by the third separation region 26. Furthermore, in the first embodiment, by disposing the third separation region 26 so as not to penetrate the semiconductor layer 20, it is possible to suppress the photodiodes 21 from being electrically separated from each other by the third separation region 26.
Description of other portions in the pixel array unit 10 will be continued. The planarizing film 30 is disposed on the light incident surface 20a of the semiconductor layer 20, and planarizes the light incident surface 20a. The planarizing film 30 is made of, for example, silicon oxide.
Note that, in the first embodiment, a fixed charge film (not illustrated) may be disposed between the photodiode 21 and each of the first separation region 24, the second separation region 25, and the planarizing film 30. Such a fixed charge film has a function of fixing a charge (here, a positive hole) to an interface between the photodiode 21 and each of the first separation region 24, the second separation region 25, and the planarizing film 30.
As a material of the fixed charge film, a high dielectric material having a large amount of fixed charges is preferably used. The fixed charge film is made of, for example, hafnium oxide (HfO2), aluminum oxide (Al2O3), tantalum oxide, zirconium oxide (ZrO2), titanium oxide, magnesium oxide (MgO2), or lanthanum oxide (La2O3).
In addition, the fixed charge film may be made of praseodymium oxide (Pr2O3) , cerium oxide (CeO2) , neodymium oxide (Nd2O3) , promethium oxide (Pm2O3) , samarium oxide (Sm2O3), europium oxide (Eu2O3), or the like.
In addition, the fixed charge film may be made of gadolinium oxide (Gd2O3), terbium oxide (Tb2O3), dysprosium oxide (Dy2O3), holmium oxide (Ho2O3), erbium oxide (Er2O3), thulium oxide (Tm2O3), or the like.
In addition, the fixed charge film may be made of ytterbium oxide (Yb2O3), lutetium oxide (Lu2O3), yttrium oxide (Y2O3), aluminum nitride (AlN), hafnium oxynitride (HfON), an aluminum oxynitride film (AlON), or the like.
The color filter 40 is an optical filter that transmits light in a predetermined wavelength region among incident light beams L, and is disposed between the on-chip lens 50 and the planarizing film 30.
The on-chip lens 50 is disposed on a side where light L is incident on the semiconductor layer 20, and has a function of condensing light L toward a corresponding light-receiving pixel 11. The on-chip lens 50 is made of, for example, an organic material or silicon oxide.
In the first embodiment, as illustrated in
Next, various modifications of the first embodiment will be described with reference to
In Modification 1 of the first embodiment, as illustrated in
The color filter 40R is a color filter 40 that transmits light in a red wavelength region among incident light beams L, and the color filters 40Gr and 40Gb are color filters 40 that transmit light in a green wavelength region among incident light beams L. The color filter 40B is a color filter 40 that transmits light in a blue wavelength region among incident light beams L.
Furthermore, inside one light-receiving pixel group 100, the color filters 40R, 40Gr, 40Gb, and 40B are arranged in a regular color array (for example, Bayer array).
In addition, the red pixel 11R included in the light-receiving pixel group 100 receives red light that has passed through the color filter 40R, photoelectrically converts a charge amount corresponding to an incident light amount of the red light, and accumulates the photoelectrically converted charge amount inside the red pixel 11R.
Similarly, the green pixels 11Gr and 11Gb receive green light that has passed through the color filters 40Gr and 40Gb, photoelectrically converts a charge amount corresponding to an incident light amount of the green light, and accumulates the photoelectrically converted charge amount inside the green pixels 11Gr and 11Gb, respectively. In addition, the blue pixel 11B receives blue light that has passed through the color filter 40B, photoelectrically converts a charge amount corresponding to an incident light amount of the blue light, and accumulates the photoelectrically converted charge amount inside the blue pixel 11B.
As described above, in the light-receiving pixel group 100 according to Modification 1 of the first embodiment, light beams in two or more (three in the example of
In addition, in Modification 1 of the first embodiment, as illustrated in
For example, as illustrated in
In addition, the green pixel 11Gr includes a third separation region 26Gr that is disposed so as to extend in a direction substantially perpendicular to the second separation region 25 in plan view and so as not to extend from one side to the other side in the rectangular first separation region 24.
In addition, the green pixel 11Gb includes a third separation region 26Gb that is disposed so as to extend in a direction obliquely intersecting with the second separation region 25 from the upper right to the lower left in plan view and so as not to extend from one side to the other side in the rectangular first separation region 24. Note that, in Modification 1 of the first embodiment, the third separation region 26 is not disposed in the blue pixel 11B.
As described above, since the plurality of light-receiving pixels 11 included in the same light-receiving pixel group 100 include the third separation regions 26 having various shapes, respectively, the degree of scattering of light L by each of the third separation regions 26 can be variously controlled. Therefore, according to Modification 1 of the first embodiment, the non-uniformity of color mixing in the pixel array unit 10 can be improved.
Note that, in Modification 1, the planar shape of the third separation region 26 disposed in each of the light-receiving pixels 11 is not limited to the example of
In Modification 2 of the first embodiment, similarly to the above-described Modification 1, the plurality of light-receiving pixels 11 included in the same light-receiving pixel group 100 include the third separation regions 26 having different shapes, respectively.
In addition, as illustrated in
As described above, since the plurality of light-receiving pixels 11 included in the same light-receiving pixel group 100 include the third separation regions 26 having various depths, respectively, the degree of scattering of light L by each of the third separation regions 26 can be variously controlled. Therefore, according to Modification 2 of the first embodiment, the non-uniformity of color mixing in the pixel array unit 10 can be improved.
In the first embodiment and the various modifications described above, the case where the second separation region 25 is oriented in the up-down direction in plan view in the light-receiving pixel 11 has been described, but the present disclosure is not limited to such an example.
As illustrated in
In addition, in Modification 3, the third separation region 26 is disposed in a direction different from a direction in which the second separation region 25 extends in plan view. As a result, since light L can be scattered in a direction different from the second separation region 25, the non-uniformity of color mixing in the pixel array unit 10 can be improved.
Furthermore, in Modification 3, the plurality of light-receiving pixels 11 included in the same light-receiving pixel group 100 include the third separation regions 26 having different shapes, respectively.
For example, as illustrated in
In addition, the green pixel 11Gb includes a third separation region 26Gb that is disposed so as to extend in a direction (up-down direction in
In addition, the green pixel 11Gr includes a third separation region 26Gr that is disposed so as to extend in a direction obliquely intersecting with the second separation region 25 from the upper left to the lower right in plan view and so as not to extend from one side to the other side in the rectangular first separation region 24. Note that, in Modification 3 of the first embodiment, the third separation region 26 is not disposed in the blue pixel 11B.
As described above, since the plurality of light-receiving pixels 11 included in the same light-receiving pixel group 100 include the third separation regions 26 having various shapes, respectively, the degree of scattering of light L by each of the third separation regions 26 can be variously controlled. Therefore, according to Modification 3 of the first embodiment, the non-uniformity of color mixing in the pixel array unit 10 can be further improved.
Note that, in Modification 3, the planar shape of the third separation region 26 disposed in each of the light-receiving pixels 11 is not limited to the example of
In Modifications 1 and 3 described above, the example in which four light-receiving pixels 11 constitute one light-receiving pixel group 100 has been described, but the present disclosure is not limited to such an example.
As illustrated in
In addition, four blue pixels 11B1 to 11B4 are arranged in two rows and two columns at the lower left of the light-receiving pixel group 100 in plan view. In addition, four green pixels 11Gb1 to 11Gb4 are arranged in two rows and two columns at the lower right of the light-receiving pixel group 100 in plan view.
In addition, in Modification 4 of the first embodiment, as illustrated in
For example, as illustrated in
In addition, the red pixel 11R1 includes a third separation region 26R1 that is disposed so as to extend in a direction obliquely intersecting with the second separation region 25 from the upper left to the lower right in plan view and so as not to extend from one side to the other side in the rectangular first separation region 24.
In addition, the red pixel 11R2 includes a third separation region 26R2 that is disposed so as to extend in a direction obliquely intersecting with the second separation region 25 from the upper right to the lower left in plan view and so as not to extend from one side to the other side in the rectangular first separation region 24.
In addition, the red pixel 11R3 includes a third separation region 26R3 that is disposed so as to extend in a direction obliquely intersecting with the second separation region 25 from the upper right to the lower left in plan view and so as not to extend from one side to the other side in the rectangular first separation region 24.
In addition, the green pixel 11R4 includes a third separation region 26R4 that is disposed so as to extend in a direction obliquely intersecting with the second separation region 25 from the upper left to the lower right in plan view and so as not to extend from one side to the other side in the rectangular first separation region 24.
In addition, the blue pixel 11B2 includes a third separation region 26B2 that is disposed so as to extend in a direction (left-right direction in
In addition, the blue pixel 11B3 includes a third separation region 26B3 that is disposed so as to extend in a direction (left-right direction in
In addition, the green pixels 11Gb3 and 11Gb4 include a third separation region 26Gb3 that is disposed so as to extend in a direction substantially perpendicular to the second separation region 25 in plan view and so as to cross the green pixels 11Gb3 and 11Gb4.
As described above, since the plurality of light-receiving pixels 11 that are included in the same light-receiving pixel group 100 and receive light of the same color include the third separation regions 26 having various shapes, respectively, the degree of scattering of light L by each of the third separation regions 26 can be variously controlled. Therefore, according to Modification 4 of the first embodiment, the non-uniformity of color mixing in the pixel array unit 10 can be further improved.
Note that, in Modification 4, the planar shape of the third separation region 26 disposed in each of the light-receiving pixels 11 is not limited to the example of
In the pixel array unit 10 including a large number of light-receiving pixels 11, a light-receiving pixel 11CC located at a central portion and a light-receiving pixel 11 (for example, a light-receiving pixel 11RU at an upper right corner) located at an end portion have different incident angles of light L coming from the on-chip lens 50.
As a result, in the light-receiving pixel 11 at the end portion, a light scattering state by the third separation region 26 is different from that in the light-receiving pixel 11CC located at the central portion. That is, in the pixel array unit 10, the light scattering state by the third separation region 26 is different between the light-receiving pixels 11 having different image heights.
Here, “image height” refers to a distance from an optical axis (for example, the center of the pixel array unit 10). In a case where the optical axis is the center of the pixel array unit 10, such a center is expressed as, for example, “the image height is low” or “image height center”, and an end portion of the pixel array unit 10 is expressed as, for example, “the image height is high” or “high image height”.
In Modification 5 of the first embodiment, the position and shape of the third separation region 26 are changed depending on the image height of the light-receiving pixel 11 on the pixel array unit 10. For example, in Modification 5, as illustrated in
For example, the light-receiving pixel 11CC at the image height center includes a third separation region 26CC whose center of gravity is disposed at a position substantially equal to the center of gravity of the light-receiving pixel 11CC. Meanwhile, the light-receiving pixel 11RU located at an upper right end portion of the pixel array unit 10 includes a third separation region 26RU whose center of gravity is disposed at a position shifted to the lower left from the center of gravity of the light-receiving pixel 11RU.
In addition, a light-receiving pixel 11CU located at an upper central end portion of the pixel array unit 10 includes a third separation region 26CU whose center of gravity is disposed at a position shifted downward from the center of gravity of the light-receiving pixel 11CU. In addition, a light-receiving pixel 11LD located at a lower left end portion of the pixel array unit 10 includes a third separation region 26LC whose center of gravity is disposed at a position shifted to the upper right from the center of gravity of the light-receiving pixel 11LD.
As described above, in the plurality of light-receiving pixels 11 having different image heights, the third separation region 26 having different positions are disposed, respectively. Therefore, the degree of scattering of light L by each of the third separation regions 26 can be variously controlled. Therefore, according to Modification 5 of the first embodiment, the non-uniformity of color mixing in the pixel array unit 10 can be further improved.
Note that, in the example of
Next, an example of a process of manufacturing the light-receiving pixel 11 according to the first embodiment will be described with reference to
In the process of manufacturing the light-receiving pixel 11, as illustrated in
As a result, a first impurity region 22 and a second impurity region 23 are formed inside the semiconductor layer 20. Note that the trench T1 is formed in a portion where the first separation region 24 and the second separation region 25 are to be disposed.
Next, an oxide film 71 is formed on the inner wall surface of the trench T1 by a conventionally known method, and a polysilicon film 72 is further formed by a conventionally known method so as to fill the remaining space of the trench T1.
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
In the silicon oxide film, the silicon oxide film formed in the trench T2 constitutes the third separation region 26, and the silicon oxide film formed in the trench T4 constitutes the second separation region 25.
As described above, in the process of manufacturing the light-receiving pixel 11 according to the first embodiment, the third separation region 26 can be formed in the same step as the second separation region 25. In addition, although detailed description is omitted, the first separation region 24 can also be formed in a similar step to the second separation region 25.
That is, according to the first embodiment, in the process of manufacturing the light-receiving pixel 11, the third separation region 26 can be formed in the same step as the first separation region 24 and the second separation region 25.
Therefore, according to the first embodiment, since the process of manufacturing the pixel array unit 10 can be simplified, cost of manufacturing the solid-state imaging element 1 can be reduced.
In addition, in the first embodiment, by using the trench T1 formed before the step of forming the wiring layer 60, the second impurity region 23 can be formed not only at the bottom portion of the first impurity region 22 but also at the side portion of the first impurity region 22.
Therefore, according to the first embodiment, since the area of a PN junction surface of the photodiode 21 can be enlarged, a saturation signal charge amount of the photodiode 21 can be increased.
In recent years, in a back irradiation type CMOS image sensor, there is a technique of causing light to be incident on a pair of photodiodes from the same on-chip lens to detect a phase difference.
In addition, by forming an impurity region in a partial region between the pair of photodiodes, the impurity region can function as an overflow path. Therefore, charge amounts accumulated in both photodiodes can be equal to each other.
However, in the above-described conventional technique, the same light obliquely incident on a light-receiving pixel disposed in a portion having a high image height may be incident on both of the pair of photodiodes via the impurity region disposed between the pair of photodiodes.
Then, the same light is incident on both of the pair of photodiodes, and a separation ratio between the pair of photodiodes thereby decreases. Therefore, accuracy of phase difference detection may decrease.
Therefore, it is expected to achieve a technique capable of overcoming the above-described problems and improving a separation ratio between the pair of photodiodes.
First, a detailed configuration of a pixel array unit 10 according to a second embodiment will be described with reference to
As illustrated in
Note that
As illustrated in
The semiconductor layer 20 contains, for example, silicon. The semiconductor layer 20 includes a plurality of photodiodes (PD) 21. The photodiode 21 is an example of a photoelectric conversion unit. Note that one light-receiving pixel 11 includes a pair of photodiodes 21 (hereinafter, also referred to as photodiodes 21L and 21R). In addition, the light-receiving pixel 11 has a substantially square shape in plan view, and the photodiode 21 has a substantially rectangular shape in plan view.
The photodiode 21 includes a first impurity region 22 containing a first conductivity type (for example, N type) impurity and a second impurity region 23 containing a second conductivity type (for example, P type) impurity.
The first impurity region 22 is disposed in a central portion of the photodiode 21, and the second impurity region 23 is disposed along a side portion and a bottom portion (a portion on a side opposite to a side on which light L is incident) of the first impurity region 22.
In addition, the light-receiving pixel 11 includes a first separation region 24, a second separation region 25, and a third separation region 26. As illustrated in
In addition, as illustrated in
As illustrated in
The second separation region 25 is made of, for example, a dielectric having a low refractive index, such as silicon oxide. As a result, the second separation region 25 can optically and electrically separate the plurality of photodiodes 21 adjacent to each other.
As described above, in the second embodiment, since the pair of photodiodes 21 can be separated from each other using the second separation region 25, a phase difference of incident light L can be detected using the pair of photodiodes 21.
In addition, in the second embodiment, the light-receiving pixel 11LC includes a second impurity region 27 disposed at a position different from the second separation region 25 in plan view between the pair of photodiodes 21 and containing a second conductivity type impurity. The second impurity region 27 is an example of an impurity region.
The second impurity region 27 functions as an overflow path between a photodiode 21L and a photodiode 21R. As a result, in the second embodiment, charge amounts accumulated in both the photodiodes 21L and 21R can be equal to each other.
Meanwhile, by forming the second impurity region 27 between the pair of photodiodes 21, adverse effects as illustrated in
As illustrated in
That is, the same light L obliquely incident on the light-receiving pixel 11LC disposed in a portion having a high image height may be incident on both the photodiodes 21L and 21R via the second impurity region 27.
Then, the same light L is incident on both the photodiodes 21L and 21R, and a separation ratio between the photodiodes 21L and 21R thereby decreases. Therefore, accuracy of phase difference detection may decrease.
Therefore, in the second embodiment, as illustrated in
Specifically, as illustrated in
In addition, the third separation region 26 is disposed so as to extend in the same direction (up-down direction in
In addition, as in the first embodiment, the third separation region 26 is disposed from a light incident surface 20a of the semiconductor layer 20 to a middle of the semiconductor layer 20 (that is, so as not to penetrate the semiconductor layer 20). The third separation region 26 is made of, for example, the same material (a dielectric having a low refractive index) as that of the second separation region 25.
By disposing such a third separation region 26 in the light-receiving pixel 11LC, as illustrated in
Therefore, according to the second embodiment, a separation ratio between the pair of photodiodes 21 can be improved.
In addition, in the second embodiment, the third separation region 26 is preferably made of the same material (for example, silicon oxide) as that of the first separation region 24 and the second separation region 25. As a result, in a process of manufacturing the light-receiving pixel 11, the third separation region 26 can be formed in the same step as the first separation region 24 and the second separation region 25.
Therefore, according to the second embodiment, since the process of manufacturing the pixel array unit 10 can be simplified, cost of manufacturing the solid-state imaging element 1 can be reduced.
Meanwhile, in the second embodiment, the third separation region 26 may be made of a material different from that of the first separation region 24 and the second separation region 25.
For example, as illustrated in
As a result, since a difference in refractive index between the third separation region 26A and the photodiode 21 can be reduced, it is possible to suppress light L incident on an end portion on a light incident side in the third separation region 26A from being largely scattered.
Therefore, according to the second embodiment, since scattered light caused by the third separation region 26A can be suppressed from leaking into another photodiode 21, occurrence of color mixing due to such scattered light can be suppressed.
Note that the planar arrangement of the third separation region 26A using a material having a high refractive index is not limited to the example of
For example, as illustrated in
Since this also makes it possible to reduce a difference in refractive index between the third separation region 26A and the photodiode 21, it is possible to suppress light L incident on an end portion on a light incident side in the third separation region 26A from being largely scattered.
Returning to
Note that, in the second embodiment, a fixed charge film (not illustrated) may be disposed between the photodiode 21 and each of the first separation region 24, the second separation region 25, and the planarizing film 30. Such a fixed charge film has a function of fixing a charge (here, a positive hole) to an interface between the photodiode 21 and each of the first separation region 24, the second separation region 25, and the planarizing film 30.
As a material of the fixed charge film, a high dielectric material having a large amount of fixed charges is preferably used. As the fixed charge film, for example, a similar material to the material of the fixed charge film according to the first embodiment described above can be used.
The color filter 40 is an optical filter that transmits light in a predetermined wavelength region among incident light beams L, and is disposed between the on-chip lens 50 and the planarizing film 30.
The on-chip lens 50 is disposed on a side where light L is incident on the semiconductor layer 20, and has a function of condensing light L toward a corresponding light-receiving pixel 11. The on-chip lens 50 is made of, for example, an organic material or silicon oxide.
In the second embodiment, as illustrated in
In addition, in the second embodiment, as illustrated in
Next, various modifications of the second embodiment will be described with reference to
Note that
In Modification 1 of the second embodiment, as illustrated in
The red pixel 11R has a color filter 40R (see
The color filter 40R is a color filter 40 that transmits light in a red wavelength region among incident light beams L, and the color filters 40Gr and 40Gb are color filters 40 that transmit light in a green wavelength region among incident light beams L. The color filter 40B is a color filter 40 that transmits light in a blue wavelength region among incident light beams L.
Furthermore, inside one light-receiving pixel group 100, the color filters 40R, 40Gr, 40Gb, and 40B are arranged in a regular color array (for example, Bayer array).
In addition, the red pixel 11R included in the light-receiving pixel group 100 receives red light that has passed through the color filter 40R, photoelectrically converts a charge amount corresponding to an incident light amount of the red light, and accumulates the photoelectrically converted charge amount inside the red pixel 11R.
Similarly, the green pixels 11Gr and 11Gb receive green light that has passed through the color filters 40Gr and 40Gb, photoelectrically converts a charge amount corresponding to an incident light amount of the green light, and accumulates the photoelectrically converted charge amount inside the green pixels 11Gr and 11Gb, respectively. In addition, the blue pixel 11B receives blue light that has passed through the color filter 40B, photoelectrically converts a charge amount corresponding to an incident light amount of the blue light, and accumulates the photoelectrically converted charge amount inside the blue pixel 11B.
As described above, in the light-receiving pixel group 100 according to Modification 1 of the second embodiment, light beams in two or more (three in the example of
In addition, in Modification 1 of the second embodiment, as illustrated in
For example, the red pixel 11R includes a third separation region 26R, the green pixels 11Gr and 11Gb include third separation regions 26Gr and 26Gb, respectively, and the blue pixel 11B includes a third separation region 26B.
By disposing such a third separation region 26 in each of the light-receiving pixels 11LC included in the same light-receiving pixel group 100, a separation ratio between the pair of photodiodes 21 can be improved in each of the light-receiving pixels 11LC.
Note that
Meanwhile, in Modification 2, unlike Modification 1 described above, the third separation region 26 is not disposed in the red pixel 11R. Since light in a red wavelength region incident on the red pixel 11R is largely scattered by the third separation region 26 as compared with light in a green or blue wavelength region, color mixing caused by the scattered light occurs to a considerable extent.
Therefore, in Modification 2, by not disposing the third separation region 26 in the red pixel 11R, occurrence of color mixing can be suppressed. In addition, in Modification 2, since the third separation region 26 is disposed in each of the green pixels 11Gr and 11Gb and the blue pixel 11B, a separation ratio between the pair of photodiodes 21 can be improved in each of the green pixels 11Gr and 11Gb and the blue pixel 11B.
That is, according to Modification 2 of the second embodiment, it is possible to achieve both suppression of color mixing and improvement of the separation ratio.
Note that
Meanwhile, in Modification 3, the planar shape of the third separation region 26B disposed in the blue pixel 11B is different from that of Modification 2 described above. Specifically, the third separation region 26B disposed in the blue pixel 11B has a substantially cross shape in plan view.
In other words, the third separation region 26B has a portion extending in the same direction (up-down direction in
As a result, light L incident on the cross-shaped third separation region 26B is scattered in various directions in the blue pixel 11B. Therefore, according to Modification 3 of the second embodiment, a saturation signal charge amount of the blue pixel 11B can be increased.
In addition, according to Modification 3 of the second embodiment, the third separation region 26 is disposed in each of the blue pixel 11B and the green pixels 11Gr and 11Gb, while the third separation region 26 is not disposed in the red pixel 11R. As a result, similarly to Modification 2 described above, it is possible to achieve both suppression of color mixing and improvement of the separation ratio.
Note that
Meanwhile, in Modification 4, the planar shape of the third separation region 26Gr disposed in the green pixels 11Gr and 11Gb is different from that of Modification 3 described above. Specifically, the third separation regions 26Gr and 26Gb disposed in the green pixels 11Gr and 11Gb, respectively each have a substantially cross shape in plan view.
As a result, light L incident on the cross-shaped third separation regions 26Gr and 26Gb is scattered in various directions in the green pixels 11Gr and 11Gb, respectively. Therefore, according to Modification 4 of the second embodiment, a saturation signal charge amount of each of the green pixels 11Gr and 11Gb can be increased.
In addition, according to Modification 4 of the second embodiment, since the cross-shaped third separation region 26B is disposed in the blue pixel 11B, a saturation signal charge amount of the blue pixel 11B can also be increased.
In addition, according to Modification 4 of the second embodiment, the third separation region 26 is disposed in each of the blue pixel 11B and the green pixels 11Gr and 11Gb, while the third separation region 26 is not disposed in the red pixel 11R. As a result, similarly to Modification 2 described above, it is possible to achieve both suppression of color mixing and improvement of the separation ratio.
Note that
As illustrated in
The red pixel 11R has a color filter 40R (see
That is, in the light-receiving pixel group 100 according to Modification 5 of the second embodiment, light beams in two or more (three in the example of
In addition, in Modification 5 of the second embodiment, as illustrated in
Specifically, the third separation region 26 according to Modification 5 of the second embodiment is disposed at a position where light L obliquely incident on the second impurity region 27 can be blocked (for example, a position closer to the image height center side with respect to the second impurity region 27).
As illustrated in
By disposing such a third separation region 26 in each of the light-receiving pixels 11LU included in the same light-receiving pixel group 100, it is possible to suppress the same light L from being incident on both of the pair of photodiodes 21 via the second impurity region 27 in each of the light-receiving pixels 11LU.
Therefore, according to Modification 5 of the second embodiment, a separation ratio between the pair of photodiodes 21 can be improved in each of the light-receiving pixels 11LU.
Note that
Meanwhile, in Modification 6, unlike Modification 5 described above, the third separation region 26 is not disposed in the red pixel 11R. Since light in a red wavelength region incident on the red pixel 11R is largely scattered by the third separation region 26 as compared with light in a green or blue wavelength region, color mixing caused by the scattered light occurs to a considerable extent.
Therefore, in Modification 6, by not disposing the third separation region 26 in the red pixel 11R, occurrence of color mixing can be suppressed. In addition, in Modification 6, since the third separation region 26 is disposed in each of the green pixels 11Gr and 11Gb and the blue pixel 11B, a separation ratio between the pair of photodiodes 21 can be improved in each of the green pixels 11Gr and 11Gb and the blue pixel 11B.
That is, according to Modification 6 of the second embodiment, it is possible to achieve both suppression of color mixing and improvement of the separation ratio.
Note that
Meanwhile, in Modification 7, the planar shape of the third separation region 26B disposed in the blue pixel 11B is different from that of Modification 6 described above. Specifically, the third separation region 26B disposed in the blue pixel 11B has a substantially cross shape in plan view.
As a result, light L incident on the cross-shaped third separation region 26B is scattered in various directions in the blue pixel 11B. Therefore, according to Modification 7 of the second embodiment, a saturation signal charge amount of the blue pixel 11B can be increased.
In addition, according to Modification 7 of the second embodiment, the third separation region 26 is disposed in each of the blue pixel 11B and the green pixels 11Gr and 11Gb, while the third separation region 26 is not disposed in the red pixel 11R. As a result, similarly to Modification 6 described above, it is possible to achieve both suppression of color mixing and improvement of the separation ratio.
Note that
Meanwhile, in Modification 8, the planar shape of the third separation region 26Gr disposed in the green pixels 11Gr and 11Gb is different from that of Modification 7 described above. Specifically, the third separation regions 26Gr and 26Gb disposed in the green pixels 11Gr and 11Gb, respectively each have a substantially cross shape in plan view.
As a result, light L incident on the cross-shaped third separation regions 26Gr and 26Gb is scattered in various directions in the green pixels 11Gr and 11Gb, respectively. Therefore, according to Modification 8 of the second embodiment, a saturation signal charge amount of each of the green pixels 11Gr and 11Gb can be increased.
In addition, according to Modification 8 of the second embodiment, since the cross-shaped third separation region 26B is disposed in the blue pixel 11B, a saturation signal charge amount of the blue pixel 11B can also be increased.
In addition, according to Modification 8 of the second embodiment, the third separation region 26 is disposed in each of the blue pixel 11B and the green pixels 11Gr and 11Gb, while the third separation region 26 is not disposed in the red pixel 11R. As a result, similarly to Modification 6 described above, it is possible to achieve both suppression of color mixing and improvement of the separation ratio.
Note that
As illustrated in
The red pixel 11R has a color filter 40R (see
That is, in the light-receiving pixel group 100 according to Modification 9 of the second embodiment, light beams in two or more (three in the example of
In addition, in Modification 9 of the second embodiment, as illustrated in
As illustrated in
However, even in such a case, by disposing the third separation region 26 as illustrated in
Note that, in the second embodiment and various modifications described above, the planar shape of the third separation region 26 disposed in the light-receiving pixel 11 is not limited to the examples of the present disclosure, and the third separation region 26 may have various planar shapes.
The solid-state imaging element 1 according to the first embodiment includes the plurality of light-receiving pixels 11 arranged in a matrix inside the semiconductor layer 20. In addition, the light-receiving pixel 11 includes the pair of photoelectric conversion units (photodiodes 21), the first separation region 24, the second separation region 25, and the third separation region 26. The pair of photoelectric conversion units (photodiodes 21) are disposed adjacent to each other. The first separation region 24 is disposed so as to surround the pair of photoelectric conversion units (photodiodes 21) and is disposed so as to penetrate the semiconductor layer 20. The second separation region 25 is disposed between the pair of photoelectric conversion units (photodiodes 21) and is disposed so as to penetrate the semiconductor layer 20. The third separation region 26 is disposed in a region surrounded by the first separation region 24 and is disposed from the light incident surface 20a of the semiconductor layer 20 to a middle of the semiconductor layer 20.
This can improve the non-uniformity of color mixing in the pixel array unit 10.
In addition, in the solid-state imaging element 1 according to the first embodiment, the third separation region 26 is disposed so as to straddle the second separation region 25 in plan view.
This can improve the non-uniformity of color mixing in the pixel array unit 10.
In addition, the solid-state imaging element 1 according to the first embodiment includes the light-receiving pixel group 100 including the plurality of light-receiving pixels 11 that receives light in two or more wavelength regions. In addition, in the plurality of light-receiving pixels 11 included in the same light-receiving pixel group 100, the third separation regions 26 having different positions and/or different shapes are disposed, respectively.
This can improve the non-uniformity of color mixing in the pixel array unit 10.
In addition, in the solid-state imaging element 1 according to the first embodiment, in the plurality of light-receiving pixels 11 having different image heights, the third separation regions 26 having different positions and/or different shapes are disposed, respectively.
This can improve the non-uniformity of color mixing in the pixel array unit 10.
In addition, the solid-state imaging element 1 according to the second embodiment includes the plurality of light-receiving pixels 11 arranged in a matrix inside the semiconductor layer 20. In addition, the light-receiving pixel 11 includes the pair of photoelectric conversion units (photodiodes 21), the first separation region 24, the second separation region 25, the impurity region (second impurity region 27), and the third separation region 26. The pair of photoelectric conversion units (photodiodes 21) are disposed adjacent to each other. The first separation region 24 is disposed so as to surround the pair of photoelectric conversion units (photodiodes 21) and is disposed so as to penetrate the semiconductor layer 20. The second separation region 25 is disposed between the pair of photoelectric conversion units (photodiodes 21) and is disposed so as to penetrate the semiconductor layer 20. The impurity region (second impurity region 27) is disposed at a position different from the second separation region 25 in plan view between the pair of photoelectric conversion units (photodiodes 21). The third separation region 26 is disposed in a region surrounded by the first separation region 24 and is disposed from the light incident surface 20a of the semiconductor layer 20 to a middle of the semiconductor layer 20.
This can improve a separation ratio between the pair of photodiodes 21.
In addition, in the solid-state imaging element 1 according to the second embodiment, the third separation region 26 is disposed adjacent to the impurity region (second impurity region 27) in plan view.
This can improve a separation ratio between the pair of photodiodes 21.
In addition, in the solid-state imaging element 1 according to the second embodiment, the third separation region 26 has a substantially cross shape in plan view.
As a result, it is possible to achieve both suppression of color mixing and improvement of the separation ratio.
In addition, in the solid-state imaging element 1 according to the second embodiment, in the plurality of light-receiving pixels 11 having different image heights, the third separation regions 26 having different positions and/or different shapes are disposed, respectively.
This can improve a separation ratio between the pair of photodiodes 21.
Note that the present disclosure is not limited to application to a solid-state imaging element. That is, the present disclosure is applicable to all electronic devices each including a solid-state imaging element, such as a camera module, an imaging device, a portable terminal device having an imaging function, or a copying machine using a solid-state imaging element in an image reading unit, in addition to the solid-state imaging element.
Examples of such an imaging device include a digital still camera and a video camera. Examples of such a portable terminal device having an imaging function include a smartphone and a tablet terminal.
In
In the electronic device 1000, the DSP circuit 1003, the frame memory 1004, the display unit 1005, the recording unit 1006, the operation unit 1007, and the power source unit 1008 are connected to each other via a bus line 1009.
The lens group 1001 captures incident light (image light) from a subject and forms an image on an imaging surface of the solid-state imaging element 1002. The solid-state imaging element 1002 corresponds to the solid-state imaging element 1 according to each of the above-described embodiments, and converts the amount of incident light imaged on the imaging surface by the lens group 1001 into an electrical signal in units of pixels and outputs the electrical signal as a pixel signal.
The DSP circuit 1003 is a camera signal processing circuit that processes a signal supplied from the solid-state imaging element 1002. The frame memory 1004 temporarily holds image data processed by the DSP circuit 1003 in units of frames.
The display unit 1005 is constituted by, for example, a panel type display device such as a liquid crystal panel or an organic electro luminescence (EL) panel, and displays a moving image or a still image imaged by the solid-state imaging element 1002. The recording unit 1006 records image data of a moving image or a still image imaged by the solid-state imaging element 1002 on a recording medium such as a semiconductor memory or a hard disk.
The operation unit 1007 issues operation commands for various functions of the electronic device 1000 in response to an operation by a user. The power source unit 1008 appropriately supplies various power sources serving as operation power sources of the DSP circuit 1003, the frame memory 1004, the display unit 1005, the recording unit 1006, and the operation unit 1007 to these supply targets.
In the electronic device 1000 configured as described above, signal quality can be improved by applying the solid-state imaging element 1 of each of the above-described embodiments as the solid-state imaging element 1002.
Although the embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments as they are, and various modifications can be made without departing from the gist of the present disclosure. In addition, components of different embodiments and modifications may be appropriately combined with each other.
In addition, the effects described here are merely examples and are not limited, and other effects may be exhibited.
Note that the present technique can also have the following configurations.
(1)
A solid-state imaging element comprising a plurality of light-receiving pixels arranged in a matrix inside a semiconductor layer, wherein
each of the light-receiving pixels includes:
a pair of photoelectric conversion units disposed adjacent to each other;
a first separation region disposed so as to surround the pair of photoelectric conversion units and disposed so as to penetrate the semiconductor layer;
a second separation region disposed between the pair of photoelectric conversion units and disposed so as to penetrate the semiconductor layer; and
a third separation region disposed in a region surrounded by the first separation region and disposed from a light incident surface of the semiconductor layer to a middle of the semiconductor layer.
(2)
The solid-state imaging element according to the above (1), wherein
the third separation region is disposed so as to straddle the second separation region in plan view.
(3)
The solid-state imaging element according to the above (1) or (2), comprising a light-receiving pixel group including the plurality of light-receiving pixels that receives light in two or more wavelength regions, wherein
in the plurality of light-receiving pixels included in the same light-receiving pixel group, the third separation regions having at least one of different positions and different shapes are disposed, respectively.
(4)
The solid-state imaging element according to to any one of the above (1) to (3), wherein
in the plurality of light-receiving pixels having different image heights, the third separation regions having at least one of different positions and different shapes are disposed, respectively.
(5)
An electronic device comprising:
a solid-state imaging element;
an optical system that captures incident light from a subject and forms an image on an imaging surface of the solid-state imaging element; and
a signal processing circuit that performs processing on an output signal from the solid-state imaging element, wherein
the solid-state imaging element includes a plurality of light-receiving pixels arranged in a matrix inside a semiconductor layer, and
each of the light-receiving pixels includes:
a pair of photoelectric conversion units disposed adjacent to each other;
a first separation region disposed so as to surround the pair of photoelectric conversion units and disposed so as to penetrate the semiconductor layer;
a second separation region disposed between the pair of photoelectric conversion units and disposed so as to penetrate the semiconductor layer; and
a third separation region disposed in a region surrounded by the first separation region and disposed from a light incident surface of the semiconductor layer to a middle of the semiconductor layer.
(6)
The electronic device according to the above (5), wherein
the third separation region is disposed so as to straddle the second separation region in plan view.
(7)
The electronic device according to the above (5) or (6), comprising a light-receiving pixel group including the plurality of light-receiving pixels that receives light in two or more wavelength regions, in which
in the plurality of light-receiving pixels included in the same light-receiving pixel group, the third separation regions having different positions and/or different shapes are disposed, respectively.
(8)
The electronic device according to any one of the above (5) to (7), wherein
in the plurality of light-receiving pixels having different image heights, the third separation regions having different positions and/or different shapes are disposed, respectively.
(9)
A solid-state imaging element including a plurality of light-receiving pixels arranged in a matrix inside a semiconductor layer, in which
each of the light-receiving pixels includes:
a pair of photoelectric conversion units disposed adjacent to each other;
a first separation region disposed so as to surround the pair of photoelectric conversion units and disposed so as to penetrate the semiconductor layer;
a second separation region disposed between the pair of photoelectric conversion units and disposed so as to penetrate the semiconductor layer;
an impurity region disposed at a position different from the second separation region in plan view between the pair of photoelectric conversion units; and
a third separation region disposed in a region surrounded by the first separation region and disposed from a light incident surface of the semiconductor layer to a middle of the semiconductor layer.
(10)
The solid-state imaging element according to the above (9), wherein
the third separation region is disposed adjacent to the impurity region in plan view.
(11)
The solid-state imaging element according to the above (9) or (10), wherein
the third separation region has a substantially cross shape in plan view.
(12)
The solid-state imaging element according to any one of the above (9) to (11), wherein
in the plurality of light-receiving pixels having different image heights, the third separation regions having different positions and/or different shapes are disposed, respectively.
(13)
An electronic device including:
a solid-state imaging element;
an optical system that captures incident light from a subject and forms an image on an imaging surface of the solid-state imaging element; and
a signal processing circuit that performs processing on an output signal from the solid-state imaging element, in which
the solid-state imaging element includes a plurality of light-receiving pixels arranged in a matrix inside a semiconductor layer, and
each of the light-receiving pixels includes:
a pair of photoelectric conversion units disposed adjacent to each other;
a first separation region disposed so as to surround the pair of photoelectric conversion units and disposed so as to penetrate the semiconductor layer;
a second separation region disposed between the pair of photoelectric conversion units and disposed so as to penetrate the semiconductor layer;
an impurity region disposed at a position different from the second separation region in plan view between the pair of photoelectric conversion units; and
a third separation region disposed in a region surrounded by the first separation region and disposed from a light incident surface of the semiconductor layer to a middle of the semiconductor layer.
(14)
The electronic device according to the above (13), wherein
the third separation region is disposed adjacent to the impurity region in plan view.
(15)
The electronic device according to the above (13) or (14), wherein
the third separation region has a substantially cross shape in plan view.
(16)
The electronic device according to any one of the above (13) to (15), wherein
in the plurality of light-receiving pixels having different image heights, the third separation regions having different positions and/or different shapes are disposed, respectively.
Number | Date | Country | Kind |
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2021-058633 | Mar 2021 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2022/005787 | 2/15/2022 | WO |