This application claims the priority benefit of Taiwan application serial no. 112131602, filed on Aug. 23, 2023. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The disclosure relates to a semiconductor power component.
In recent years, in response to the demand for high-frequency semiconductor devices, semiconductor power devices have developed into III-V semiconductor power devices, such as AlGaN—GaN HEMT devices. The AlGaN—GaN HEMT device is a high electron mobility transistor with AlGaN as the Schottky barrier. Due to spontaneous polarization and piezoelectric polarization effects, a two-dimensional electron gas (2DEG) layer is formed at the interface between the AlGaN layer and the GaN channel layer. Through factors such as the high electron mobility of the electron itself, the high concentration of electrons in the 2DEG, and the low sheet resistance of gallium nitride, III-V semiconductor materials are suitable for high-frequency applications.
As semiconductor devices develop towards higher frequency and higher voltage systems, the breakdown voltage and critical electric field that the above-mentioned III-V semiconductor materials can withstand have reached the limits. The current research and development trend of semiconductor power devices is towards higher frequency and higher voltage semiconductor devices, such as semiconductor power devices consisting of gallium oxide (Ga2O3) material with high energy gap (Eg=4.9 eV).
However, since the Ga2O3 material itself has a problem of low electron mobility, the on-resistance of the semiconductor power device can increase. In addition, since the Ga2O3 material is an oxide, semiconductor power devices are also prone to heat accumulation problems.
The semiconductor power device provided by the disclosure can increase the concentration of two-dimensional electron gas (2DEG) in a non-gate region and reduce the on-resistance.
A semiconductor power device of the disclosure includes a substrate, a channel layer, a barrier layer, a gate, a source, and a drain. The channel layer is located on the substrate. The barrier layer is located on the channel layer. The barrier layer includes a first region and a second region outside the first region. There is a first compound in the first region and a second compound in the second region. The first compound and the second compound each have an aluminum atom of a different ratio. The ratio consists of a plurality of different atoms in the first compound and the second compound. The source and the drain are respectively located on the second region. The gate is located between the source and the drain and on the first region. The gate, the source, and the drain each comprise Au, Al, Ti, Sn, Ge, In, Ni, Co, Pt, W, Mo, Cr, Cu, Pb, Ti/Al, Ti/Au, Ti/Pt, Al/Au, Ni/Au, or Au/Ni.
Another semiconductor power device of the disclosure includes a substrate, a channel layer, a barrier layer, a gate, an insulating layer, a source, and a drain. The channel layer is located on the substrate. The barrier layer is located on the channel layer and has an opening. The barrier layer is an aluminum compound. The aluminum compound includes an aluminum atom consisting of one ratio and a gallium atom consisting of another ratio, which represents that the gallium atom replaces a part of the aluminum atom. A gate is located on the barrier layer and filled in the opening. The insulating layer is located between the gate and the channel layer and is in direct contact with the channel layer. The source and drain are respectively located on the barrier layer on two sides of the gate.
Another semiconductor power device of the disclosure has at least one original physical property before being doped with an aluminum ion, and the aluminum ion improves the original physical property after the semiconductor power device is doped with the aluminum ion. The semiconductor power device doped with the aluminum ion includes a substrate, a channel layer, a barrier layer, a gate, an insulating layer, a source, and a drain. The substrate is represented by a first chemical formula. The first chemical formula includes an element semiconductor or a compound semiconductor. The channel layer is located on the substrate and is represented by a second chemical formula. The second chemical formula includes another compound semiconductor. The barrier layer is located on the channel layer. The barrier layer includes at least one compound. The compound located in at least one region of the barrier layer is represented by a third chemical formula. The compound consists of a ratio of aluminum atom. The source and the drain are compositions having a metal material. The source and the drain are each independently located on the region. The gate is a metal composition. The gate is located between the source and the drain and outside the region.
Based on the above, the semiconductor power device of the disclosure can reduce the resistance of the non-gate region through a barrier layer of the non-gate region with a high Al composition ratio. Whether it is a GaN-based semiconductor power device or a semiconductor power device using Ga2O3, the on-resistance of the device can be reduced and the problem of heat accumulation can be solved. At the same time, the disclosure can appropriately reduce the Al composition ratio around the channel in the semiconductor power device to avoid an increase in stress, thereby improving the reliability of the gate. In addition, the barrier layer with a relatively low Al composition ratio under the gate can make the critical voltage value (Vt) of the device closer to a “positive value”, that is, close to the operation of an enhancement mode (E-mode) transistor, which is convenient for device applications.
The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate example embodiments and, together with the description, serve to explain the principles of the disclosure.
Referring to
The barrier layer 104 includes at least one compound. The compound located in at least one region of the barrier layer 104 is represented by a third chemical formula. The compound includes an aluminum atom consisting of a ratio. For example, the barrier layer 104 in the first embodiment includes a first region 104a and a second region 104b outside the first region 104a. There is a first compound in the first region 104a and a second compound in the second region 104b. The first compound and the second compound each have an aluminum atom of a different ratio. The ratio consists of a plurality of different atoms in the first compound and the second compound. In other words, the first compound includes one aluminum atom consisting of a first ratio, the second compound includes another aluminum atom consisting of a second ratio, and the first ratio and the second ratio are different. In the first embodiment, the first ratio is less than the second ratio; that is, the aluminum composition ratio of the first compound is less than the aluminum composition ratio of the second compound.
In an embodiment, the first compound further includes one gallium atom, which replaces a part of the aluminum atom in the first compound. The second compound further includes another gallium atom, which replaces a part of the said aluminum atom in the second compound. For example, the first compound in the first region 104a of the barrier layer 104 is AlxGa(1−x)N, and the second compound in the second region 104b of the barrier layer 104 is AlyGa(1−y)N, where x represents the first ratio and y represents the second ratio, and y>x>0. The first compound in the first region 104a of the barrier layer 104 is InxGa(1−x)N, and the second compound in the second region 104b of the barrier layer 104 is AlyInxGa(1−x−y)N, where x represents the first ratio and y represents the second ratio, and y>0, (x+y)<1. The first compound in the first region 104a of the barrier layer 104 is (AlxGa1−x)2O3, and the second compound in the second region 104b of the barrier layer 104 is (AlyGa1−y)2O3, where x represents the first ratio and y represents the second ratio, and y>x>0; and so on.
The manufacturing method of the barrier layer 104 can be, for example, but not limited to: after epitaxially growing the buffer layer 106, the channel layer 102, and the barrier layer on the substrate 100 (for example, fully forming the first compound), firstly forming the gate G on the surface of the barrier layer, and then performing an aluminum (Al+) ion implantation process to dope the second region 104b outside the first region 104a with aluminum, so that at least one of the original physical properties (such as carrier concentration, etc.) that the semiconductor power device 10a has before being doped with an aluminum ion is improved due to being doped with the aluminum ion. After the aluminum ion implantation process, the first compound in the second region 104b becomes a second compound with a larger aluminum composition ratio. The aluminum composition ratio of the second compound in the second region 104b can be converted through material analysis (such as EDS analysis).
Continuing to refer to
The carrier concentration relationship of the first region 104a below the gate G (low Al composition ratio region) and the second region 104b outside the gate G (high Al composition ratio region) is as shown in
That is to say, in
Moreover, when the channel layer 102 is a gallium oxide (β-Ga2O3) material, since β-Ga2O3 has a high energy gap (Eg=4.9 eV) and a high dielectric collapse electric field (Ec=6.5 MV/cm) but an electron mobility of only about 200 cm2/V·s, doping aluminum to increase the aluminum composition ratio of the second compound in the second region 104b can increase the electron mobility of β-Ga2O3 and reduce the on-resistance Ron, which is critical to the development of gallium oxide power devices.
Continuing to refer to
The following experiment examples are illustrated by simulation to describe the effect of the disclosure, but the disclosure is not limited to the following contents.
The simulated semiconductor power device was shown in
Referring to
Referring to
In the third embodiment, the manufacturing method of the semiconductor power device 10c includes, but is not limited to, after epitaxially growing the buffer layer 106, the channel layer 102, and the barrier layer on the substrate 100 (for example, fully forming the first compound), firstly forming a first patterned mask (not shown) on the surface of the barrier layer to cover the first region 110a, and then performing an aluminum (Al+) ion implantation process to dope the second region 110b outside the first region 110a with aluminum, so that the first compound in the second region 110b becomes a second compound with a larger aluminum composition ratio. Next, after removing the first patterned mask, a second patterned mask (not shown) is used to cover the second region 110b, and then etching is performed to form a notch 114. Then, after removing the second patterned mask, the dielectric layer 116 is formed on the surface of the barrier layer 110 (including the first region 110a and the second region 110b), and then the gate G is formed to fill the notch 114. Finally, the source S and the drain D are formed through the dielectric layer 116 to be in contact with the second region 110b.
Referring to
Continuing to refer to
In summary, the disclosure increases the aluminum composition ratio of the compound in the region outside the gate through ion implantation, thereby increasing the electron concentration of the two-dimensional electron gas (2DEG) of the region and reducing the on-resistance (Ron) of the overall device. Whether it is a GaN-based semiconductor power device or a semiconductor power device using Ga2O3, doping with an aluminum ion can effectively reduce the on-resistance of the device, and especially improving the electron mobility of β-Ga2O3 and solving the problem of heat accumulation. In other words, doping the aluminum ion to form a ratio of aluminum compounds in semiconductor power devices is critical to the development of gallium oxide power devices. In addition, the disclosure can appropriately reduce the aluminum composition ratio of the compound in the region below the gate to avoid an increase in barrier layer stress, thereby improving the reliability of the gate. In addition, the semiconductor power device of the disclosure can be a depletion mode (D-mode) transistor or an enhancement mode (E-mode) transistor, and so has wider applicability.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In diagram of the forwarding, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.
Number | Date | Country | Kind |
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112131602 | Aug 2023 | TW | national |