Epitaxial structure

Patent metadata

Field	Value
Publication number	US-11588015-B2
Application number	US-202217689997-A
Country	US
Kind code	B2
Filing date	Mar 9, 2022
Priority date	Aug 1, 2018
Publication date	Feb 21, 2023
Grant date	Feb 21, 2023

Abstract

An epitaxial structure includes a substrate, a nucleation layer on the substrate, a buffer layer on the nucleation layer, and a nitride layer on the buffer layer. The nucleation layer consists of regions in a thickness direction, wherein a chemical composition of the regions is Al(1-x)InxN, where 0≤x≤1. A maximum value of the x value in the plurality of regions is the same, a minimum value of the x value in the plurality of regions is the same, and an absolute value of a gradient slope of each of the regions is 0.1%/nm to 50%/nm. A thickness of the nucleation layer is less than a thickness of the buffer layer. A roughness of a surface of the nucleation layer in contact with the buffer layer is greater than a roughness of a surface of the buffer layer in contact with the nitride layer.

First claim

What is claimed is:

1. An epitaxial structure comprising:
a substrate;
a nucleation layer disposed on the substrate, wherein the nucleation layer consists of a plurality of regions in a thickness direction, and a chemical composition of the plurality of regions is Al (1-x) In x N, where 0≤x≤1, wherein a maximum value of the x value in the plurality of regions is the same, a minimum value of the x value in the plurality of regions is the same, and an absolute value of a gradient slope of each of the regions is 0.1%/nm to 50%/nm;
a buffer layer disposed on the nucleation layer, wherein a thickness of the nucleation layer is less than a thickness of the buffer layer; and
a nitride layer disposed on the buffer layer, wherein a roughness of a surface of the nucleation layer in contact with the buffer layer is greater than a roughness of a surface of the buffer layer in contact with the nitride layer.

2. The epitaxial structure according to claim 1 , wherein the absolute value of the gradient slope of each of the regions is 0.5%/nm to 10%/nm.

3. The epitaxial structure according to claim 1 , wherein an initial content of the x value of the nucleation layer is 10% to 100%, an end content of the x value is 0% to 90%, and an initial content of the (1-x) value is 0% to 90%, and an end content of the (1-x) value is 10% to 100%, wherein the initial content of the x value is located on a bottom portion of the nucleation layer close to the substrate, and the end content of the x value is located on a top portion of the nucleation layer close to the buffer layer.

4. The epitaxial structure according to claim 3 , wherein the initial content of the x value of the nucleation layer is 50% to 100%, the end content of the x value is 0% to 50%, the initial content of the (1-x) value is 0% to 50%, and the end content of the (1-x) value is 50% to 100%.

5. The epitaxial structure according to claim 1 , wherein the thickness of the nucleation layer is 1 nm to 500 nm.

6. The epitaxial structure according to claim 5 , wherein the thickness of the nucleation layer is 1 nm to 50 nm.

7. The epitaxial structure according to claim 1 , wherein a number of the plurality of regions of the nucleation layer is 2 to 100.

8. The epitaxial structure according to claim 7 , wherein the number of the plurality of regions of the nucleation layer is 2 to 20.

9. The epitaxial structure according to claim 1 , wherein the roughness of the surface of the nucleation layer in contact with the buffer layer is 1 nm to 10 nm.

10. The epitaxial structure according to claim 9 , wherein the roughness of the surface of the nucleation layer in contact with the buffer layer is 1 nm to 3 nm.

Assignees

• Globalwafers Co Ltd

Inventors

• Liu Jia-Zhe
• Huang Yen-Lun
• Shih Ying-Ru

Classifications

• H10P14/3416

  Nitrides · CPC title

• H10P14/3216 Primary

  Nitrides · CPC title

• H10P14/3254

  Graded layers · CPC title

• H10P14/3251

  consisting of three or more layers · CPC title

• H10P14/3248

  consisting of two layers · CPC title