Gallium-nitride-based compound semiconductor device

• US 20030222266A1
• Filed: 02/28/2003
• Published: 12/04/2003
• Est. Priority Date: 02/28/2002
• Status: Active Grant

• Current Assignee: Nitride Semiconductors Co., Ltd., Shiro Sakai
• Original Assignee: Nitride Semiconductors Co., Ltd., Shiro Sakai
• Inventors: Naoi, Yoshiki, Tsukihara, Masashi, Sakai, Shiro
• Granted Patent: US 7,005,685 B2
• Time in Patent Office: Days
• US Class Current: 257/94
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02461 Phosphides
• CPC Class Codes: H01L 21/0254 Nitrides
• 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 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A GaN-based compound semiconductor device formed by sequentially forming, on a substrate, a GaN-based buffer layer and a GaN-based compound semiconductor layer. Al_xGa_1-xN_1-yP_y or Al_xGa_1-xN_1-yAs_y (0≦x≦1, 0<y<1) is used as the GaN-based buffer layer. N in Al_xGa_1-xN is partially substituted by P or As, whereby a buffer layer is grown at a high temperature. Thus, a difference in processing temperature between the process for growing a buffer layer and processes before and after the process is reduced. The GaN-based compound semiconductor layer formed on the buffer layer comprises a GaN-based layer, an n-type clad layer, a light-emitting layer, and a p-type clad layer. A multiple quantum well (MQW) layer formed from GaNP or GaNAs and GaN is inserted between the GaN-based layers, thereby reducing a dislocation density of the GaN-based layers.

Claims

1. A gallium-nitride-based compound semiconductor device, comprising:

a substrate;

a GaN-based buffer layer formed on said substrate; and

a GaN-based compound semiconductor layer formed on said GaN-based buffer layer, wherein

said GaN-based buffer layer comprises Al_xGa_1-xN_1-yP_y (0≦

x≦

1, 0<

y<

1).

2. The device according to claim 1, wherein said Al_xGa_1-xN_1-yP_y satisfies 0<

y≦

0.01.

3. The device according to claim 1, wherein said GaN-based buffer layer is formed at a temperature of 500°

C. or more.

4. The device according to claim 1, wherein said GaN-based buffer layer and said GaN-based compound semiconductor layer are formed at a temperature of about 1000°

C.

5. The device according to claim 1, wherein said GaN-based compound semiconductor device comprises:

a GaN-based layer formed on said GaN-based buffer layer;

a GaN-based clad layer of first conductivity type formed an said GaN-based layer;

a light-emitting layer formed on said GaN-based clad layer of first conductivity type; and

a GaN-based clad layer of second conductivity type formed on said light-emitting layer.

6. The device according to claim 1, wherein said GaN-based buffer layer is formed by an MOCVD method usinq a raw material gas containing P.

7. A gallium-nitride-based compound semiconductor device, comprising:

a substrate;

a GaN-based buffer layer formed on said substrate; and

a GaN-based compound semiconductor layer formed on said GaN-based buffer layer, wherein

said GaN-based buffer layer comprises Al_xGa_1-xN_1-yAs_y (0≦

x≦

1, 0<

y<

1).

8. The device according to claim 7, wherein said Al_xGa_1-xN_1-yAs_y satisfies 0<

y≦

0.01.

9. The device according to claim 7, wherein said GaN-based buffer layer is formed at a temperature of 500°

C. or more.

10. The device according to claim 7, wherein said GaN-based buffer layer and said GaN-based compound semiconductor layer are formed at a temperature of about 1000°

C.

11. The device according to claim 7, wherein said GaN-based compound semiconductor device comprises:

a GaN-based layer formed on said GaN-based buffer layer;

a GaN-based clad layer of first conductivity type formed on said GaN-based layer;

a GaN-based light-emitting layer formed on said GaN-based clad layer of first conductivity type; and

a GaN-based clad layer of second conductivity type formed on said light-emitting layer.

12. The device according to claim 7, wherein said GaN-based buffer layer is formed by an MOCVD method using a raw material gas containing As.

13. A gallium-nitride-based compound semiconductor device, comprising:

a substrate;

a GaN-based buffer layer formed on said substrate;

a first GaN-based layer formed on said GaN-based buffer layer;

a multiple quantum well (MQW) layer formed on said first GaN-based layer by alternately stacking GaN_1-yP_y(0<

y<

1) and GaN; and

a second GaN-based layer formed on said MQW layer.

14. The device according to claim 13, wherein said GaN_1-yP_y satisfies 0.0001≦

y≦

0.005.

15. The device according to claim 13, wherein said GaN_1-yP_y satisfies 0.0005≦

y≦

0.002.

16. The device according to claim 13, wherein the thickness “

t”

of said GaN_1-yP_y satisfies 1 nm≦

t≦

5 nm.

17. The device according to claim 13, wherein the thickness “

t”

of said GaN_1-yP_y satisfies 1 nm≦

t≦

3 nm.

18. The device according to claim 13, wherein a periodicity “

p”

of said MQW layer satisfies 1≦

p≦

20.

19. The device according to claim 13, further comprising:

a GaN-based clad layer of first conductivity type formed on said second GaN-based layer;

a GaN-based light-emitting layer formed on said GaN-based clad layer of first conductivity type; and

a GaN-based clad layer of second conductivity type formed on the GaN-based light-emitting layer.

20. The device according to claim 13, wherein said GaN-based buffer layer contains Al_xGa_1-xN_1-yP_y (0≦

x≦

1, 0≦

y≦

1).

21. The device according to claim 13, wherein said GaN-based buffer layer contains Al_xGa_1-xN_1-yAs_y (0≦

x≦

1, 0≦

y≦

1).

22. A gallium-nitride-based compound semiconductor device, comprising:

a substrate;

a GaN-based buffer layer formed on said substrate;

a first GaN-based layer formed on said GaN-based buffer layer;

a multiple quantum well (MQW) layer formed on said first GaN-based layer by alternately stacking GaN_1-yAs_y (0<

y<

1) and GaN; and

a second GaN-based layer formed on said MQW layer.

23. The device according to claim 22, wherein said GaN_1-yAs_y satisfies 0.0001≦

y≦

0.005.

24. The device according to claim 22, wherein said GaN_1-yAs_y satisfies 0.0005≦

y≦

0.002.

25. The device according to claim 22, wherein the thickness “

t”

of said GaN_1-yAs_y satisfies 1 nm≦

t≦

5 nm.

26. The device according to claim 22, wherein the thickness “

t”

of said GaN_1-yAs_y satisfies 1 nm≦

t≦

3 nm.

27. The device according to claim 22, wherein a periodicity “

p”

of said MQW layer satisfies 1≦

p≦

20.

28. The device according to claim 22, further comprising:

a GaN-based clad layer of first conductivity type formed on said second GaN-based layer;

a GaN-based light-emitting layer formed on said GaN-based clad layer of first conductivity type; and

a GaN-based clad layer of second conductivity type formed on the GaN-based light-emitting layer.

29. The device according to claim 22, wherein said GaN-based buffer layer contains Al_xGa_1-xN_1-yP_y (0≦

x≦

1, 0≦

y≦

1).

30. The device according to claim 22, wherein said GaN-based buffer layer contains Al_xGa_1-xN_1-yAs_y (0≦

x≦

1, 0≦

y≦

1).