EP-4742855-A1 - EPITAXIAL WAFER, RADIO FREQUENCY DEVICE, TERMINAL RADIO FREQUENCY MODULE, AND TERMINAL DEVICE

Abstract

Embodiments of this application provide an epitaxial wafer (100), a radio frequency device (1), a terminal radio frequency module, a terminal device. For the epitaxial wafer (100), the epitaxial wafer (100) includes a silicon substrate layer (10) and an epitaxial layer (20) that are stacked. The epitaxial layer (20) further includes a nucleation layer (201) that is stacked on a surface of the silicon substrate layer (10). In addition, air gaps are provided at an interface between the silicon substrate layer (10) and the nucleation layer (201). The epitaxial wafer (100) may be configured to provide a radio frequency device with a low radio frequency loss based on a special structure and a parameter design at the interface between the silicon substrate layer (10) and the nucleation layer (201) of the epitaxial wafer (100).

Inventors

• MA, Cheng
• HAN, Mingtao
• ZHENG, Dingheng
• ZHANG, YAWEN
• SU, SHUAI
• WEI, WEI
• HOU, Mingchen
• WU, LONG
• TANG, Yongjun
• FENG, Peng

Assignees

• Huawei Technologies Co., Ltd.

Dates

Publication Date

20260513

Application Date

20241025

Claims (20)

1. An epitaxial wafer, comprising a silicon substrate layer and an epitaxial layer that are stacked, wherein the epitaxial layer comprises a nucleation layer stacked on a surface of the silicon substrate; a surface that is of the silicon substrate layer and that is close to the nucleation layer has a plurality of first blind holes, a surface that is of the nucleation layer and that is close to the silicon substrate layer has a plurality of second blind holes, any one of the second blind holes is provided corresponding to one first blind hole, and an orthographic projection of the second blind hole on the silicon substrate layer overlaps the corresponding first blind hole; and a depth of the first blind hole is greater than or equal to 200 nm.
2. The epitaxial wafer according to claim 1, wherein the depth of the first blind hole is from 200 nm to 500 nm.
3. The epitaxial wafer according to claim 1 or 2, wherein a quantity of the second blind holes is the same as a quantity of the first blind holes, and the plurality of first blind holes are provided in a one-to-one correspondence with the plurality of second blind holes.
4. The epitaxial wafer according to any one of claims 1 to 3, wherein a depth of the second blind hole is from 300 nm to 500 nm.
5. The epitaxial wafer according to any one of claims 1 to 4, wherein an inner diameter of the first blind hole is equal everywhere in a stacking direction of the silicon substrate layer and the epitaxial layer.
6. The epitaxial wafer according to any one of claims 1 to 5, wherein an included angle between a side wall of the first blind hole and the surface that is of the silicon substrate layer and that is close to the nucleation layer is from 85° to 90°.
7. The epitaxial wafer according to any one of claims 1 to 6, wherein an opening diameter of the first blind hole is from 100 nm to 1000 nm.
8. The epitaxial wafer according to any one of claims 1 to 7, wherein an opening shape of the first blind hole is a circle or an n-sided polygon, and n>8.
9. The epitaxial wafer according to any one of claims 1 to 8, wherein the plurality of first blind holes are periodically arranged in a first direction, and the first direction is perpendicular to a stacking direction of the silicon substrate layer and the nucleation layer; and in the first direction, a minimum distance between openings of two adjacent first blind holes on the silicon substrate layer is from 200 nm to 1000 nm.
10. The epitaxial wafer according to claim 9, wherein the plurality of first blind holes are periodically arranged in a regular hexagon in the first direction.
11. The epitaxial wafer according to any one of claims 1 to 10, wherein the nucleation layer is a two-dimensional nucleation layer.
12. The epitaxial wafer according to claim 11, wherein a thickness of the nucleation layer is from 300 nm to 1000 nm.
13. The epitaxial wafer according to any one of claims 1 to 10, wherein the nucleation layer comprises a two-dimensional nucleation layer and a three-dimensional nucleation layer that are sequentially stacked, and the two-dimensional nucleation layer is disposed close to the silicon substrate layer.
14. The epitaxial wafer according to claim 13, wherein a thickness of the two-dimensional nucleation layer is from 300 nm to 500 nm, and a thickness of the three-dimensional nucleation layer is from 200 nm to 500 nm.
15. The epitaxial wafer according to any one of claims 1 to 14, wherein the nucleation layer is an aluminum nitride layer.
16. The epitaxial wafer according to any one of claims 11 to 15, wherein a dislocation density of the two-dimensional nucleation layer is less than 5×10 9 /cm 2 , and surface roughness of the two-dimensional nucleation layer is less than 0.5 nm.
17. The epitaxial wafer according to any one of claims 11 to 16, wherein a molar ratio of a group V element to a group III element on the two-dimensional nucleation layer is 1:(20-100).
18. The epitaxial wafer according to claim 13 or 14, wherein a molar ratio of a group V element to a group III element on the three-dimensional nucleation layer is 1:(100-2000).
19. The epitaxial wafer according to any one of claims 1 to 18, wherein the epitaxial layer further comprises a stress regulation layer, a high-resistance buffer layer, a channel layer, an insertion layer, a barrier layer, and a cap layer that are sequentially stacked; and the stress regulation layer is disposed on a surface that is of the nucleation layer and that is away from the silicon substrate layer.
20. The epitaxial wafer according to any one of claims 1 to 19, wherein a room-temperature resistivity of the silicon substrate layer is greater than or equal to 2000 Ω·cm.

Description

This application claims priority to Chinese Patent Application No. 202311422361.0, filed with the China National Intellectual Property Administration on October 28, 2023 and entitled "EPITAXIAL WAFER, RADIO FREQUENCY DEVICE, TERMINAL RADIO FREQUENCY MODULE, AND TERMINAL DEVICE", which is incorporated herein by reference in its entirety. TECHNICAL FIELD Embodiments of this application relate to the field of semiconductor technologies, and specifically, to an epitaxial wafer, a radio frequency device, a terminal radio frequency module, and a terminal device. BACKGROUND Currently, most radio frequency devices use group III nitride semiconductor devices represented by gallium nitride (GaN), especially a GaN-based radio frequency device that is of a heterostructure and that is based on a silicon carbide substrate. Theoretically, the structure may also be grown on a silicon substrate, and the silicon substrate may be configured to prepare a large-size and low-cost radio frequency device. However, using the silicon substrate may cause a severe radio frequency loss in the radio frequency device, and reduces working efficiency of the radio frequency device. To reduce a severe radio frequency loss caused by silicon substrate conductivity in a GaN-based radio frequency integrated circuit device on the silicon substrate, a silicon wafer with a high resistivity is usually used as the silicon substrate in the industry, but improvement effect is limited. This is largely due to that a parasitic conductive channel exists at an interface between the silicon substrate and a GaN-based epitaxial structure. In view of this, a person skilled in the art attempts to remove portions of the silicon substrates to eliminate the parasitic conductive channel at the interface between the silicon substrate and the epitaxial structure. However, such an operation is difficult in a process, and also affects structural stability of the radio frequency device, and is also not conductive to promoting and applying the GaN-based radio frequency integrated circuit device. Therefore, there is an urgent need to provide a new epitaxial wafer that can reduce the radio frequency loss of the silicon substrate and ensure structural stability and quality of the epitaxial structure and the radio frequency device. SUMMARY In view of this, embodiments of this application provide an epitaxial wafer, a radio frequency device, a terminal radio frequency module, and a terminal device. The epitaxial wafer may be configured to provide a radio frequency device with a low radio frequency loss based on a special structure and a parameter design at an interface between a silicon substrate layer and a nucleation layer of the epitaxial wafer. A first aspect of embodiments of this application provides an epitaxial wafer, including a silicon substrate layer and an epitaxial layer that are stacked. The epitaxial layer includes a nucleation layer stacked on a surface of the silicon substrate. A surface that is of the silicon substrate layer and that is close to the nucleation layer has a plurality of first blind holes, and a surface that is of the nucleation layer and that is close to the silicon substrate layer has a plurality of second blind holes. Any one of the second blind holes is provided corresponding to one first blind hole, and an orthographic projection of the second blind hole on the silicon substrate layer overlaps the corresponding first blind hole. A depth of the first blind hole is greater than or equal to 200 nm. According to the foregoing special structure design, there may be a plurality of "air gaps" at an interface between the silicon substrate layer and the nucleation layer. In addition, a depth of the "air gap" at the silicon substrate layer is greater than or equal to 200 nm, and a parasitic conductive channel at the interface between the silicon substrate layer and the nucleation layer can be effectively cut off. This can better suppress parasitic conductivity effect at the interface. Further, the epitaxial wafer can be configured to provide a radio frequency device with a low radio frequency loss. In some implementations of this application, the depth of the first blind hole is from 200 nm to 500 nm. Controlling the depth of the first blind hole to be within the foregoing range allows the air gaps formed by the first blind holes to fully exert effect of cutting off the parasitic conductive channel between the silicon substrate layer and the nucleation layer, and can also ensure that the silicon substrate layer has a strong support force for a superimposed structure on a surface of the silicon substrate layer. In this way, the epitaxial wafer is easy to prepare, and crystal quality of the epitaxial layer is high. When the epitaxial wafer is applied to the radio frequency device, this is more conductive to improving a power and efficiency of a radio frequency device. In some implementations of this application, a quantity of the second blind holes is