Method for producing group III nitride semiconductor light-emitting device

• US 8,765,509 B2
• Filed: 09/23/2011
• Issued: 07/01/2014
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Nitta, Shugo, Saito, Yoshiki, Shinoda, Daisuke
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): THOMAS, TONIAE M
• Application Number:
  US13/137,997
• Publication Number:
  US 20120083063A1
• Time in Patent Office: 1,012 Days
• Field of Search: 438/94, 438/931, 438/47, 257/77, 257/85, 257/E33.028
• US Class Current: 438/47
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/0243 Surface structure
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate

Abstract

A method for producing a Group III nitride semiconductor light-emitting device includes an n-type layer, a light-emitting layer, and a p-type layer, each of the layers being formed of Group III nitride semiconductor, being sequentially deposited via a buffer layer on a textured sapphire substrate. A buried layer is formed of Group III nitride semiconductor on the buffer layer, at a temperature lower by 20° C. to 80° C. than the temperature of 1000° C. to 1200° C. when the n-type layer is deposited on the buried layer. The texture provided on the sapphire substrate may have a depth of 1 μm to 2 μm and a side surface inclined by 40° to 80°. A preventing layer may be formed of GaN at 600° C. to 1050° C. so as to cover the entire top surface of the buffer layer.

Claims

1. A method for producing a Group III nitride semiconductor light-emitting device comprising an n-type layer, a light-emitting layer, and a p-type layer, which are made of Group III nitride semiconductor, sequentially deposited on a buffer layer which is deposited on a sapphire substrate having a c-plane main surface, said main surface having a texture structure, the method comprising:

forming the texture on the main surface of the sapphire substrate so as to have a depth of 1 μ

m to 2 μ

m;

forming a buried layer of Group III nitride semiconductor on the buffer layer, to flatten a top surface by burying the texture, at a temperature which is lower by 20°

C. to 80°

C. than that when the n-type layer is formed; and

forming the n-type layer on the buried layer at a temperature of 1000°

C. to 1200°

C.,

wherein a side surface of the texture provided on the sapphire substrate is inclined by 40°

to 80°

.

2. A method for producing a Group III nitride semiconductor light-emitting device according to claim 1, wherein the buried layer is doped with Si.

3. A method for producing a Group III nitride semiconductor light-emitting device according to claim 1, wherein the buried layer has a thickness of 1 μ

m to 3 μ

m.

4. A method for producing a Group III nitride semiconductor light-emitting device according to claim 1, wherein the buffer layer is formed of AlN.

5. A method for producing a Group III nitride semiconductor light-emitting device comprising an n-type layer, a light-emitting layer, and a p-type layer, which are made of Group III nitride semiconductor, sequentially deposited on a buffer layer which is deposited on a sapphire substrate having a c-plane main surface, said main surface having a texture structure, the method comprising:

forming the texture on the sapphire substrate so as to have a side surface inclined by 40°

to 80° and

a depth of 1 μ

m to 2 μ

m;

forming a preventing layer of Group III nitride semiconductor on the buffer layer to prevent mass transport of the buffer layer, at a temperature of 600°

C. to 1050°

C. so as to cover the entire top surface of the buffer layer; and

forming the n-type layer on the preventing layer at a temperature of 1050°

C. to 1200°

C.

6. A method for producing a Group III nitride semiconductor light-emitting device according to claim 5, wherein the buffer layer is formed of AlN;

and the preventing layer is formed at a temperature of 900°

C. to 1050°

C.

7. A method for producing a Group III nitride semiconductor light-emitting device according to claim 5, wherein the buffer layer is formed of GaN;

and nitrogen is used as a carrier gas in heating to form the n-type layer.

8. A method for producing a Group III nitride semiconductor light-emitting device according to claim 5, wherein the preventing layer has a thickness of 20 nm to 1000 nm.

9. A method for producing a Group III nitride semiconductor light-emitting device comprising layers which are made of Group III nitride semiconductor, sequentially deposited on a buffer layer which is deposited on a sapphire substrate having a c-plane main surface, said main surface having a texture structure, the method comprising:

forming the texture on the sapphire substrate so as to have a depth of 1.2 μ

m to 2.5 μ

m and a side surface inclined by 40°

to 80° and

;

forming the buffer layer of Group III nitride semiconductor containing Al.

10. A method for producing a Group III nitride semiconductor light-emitting device according to claim 9, wherein the buffer layer is formed of AlGaN having an Al composition ratio of 50% or more.

11. A method for producing a Group III nitride semiconductor light-emitting device according to claim 10, wherein the buffer layer is formed of AlN.

12. A method for producing a Group III nitride semiconductor light-emitting device according to claim 9, wherein heat treatment is performed in a hydrogen atmosphere at a temperature of 1000°

C. to 1200°

C. before forming the buffer layer after the formation of the sapphire substrate.