Semiconductor light-emitting element and method for manufacturing the same

• US 5,990,495 A
• Filed: 07/18/1996
• Issued: 11/23/1999
• Est. Priority Date: 08/25/1995
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ohba, Yasuo
• Primary Examiner(s): Kelley, Nathan K.
• Application Number:
  US08/683,381
• Time in Patent Office: 1,223 Days
• Field of Search: 257/77, 257/76, 257/94, 257/79, 257/12, 257/13
• US Class Current: 257/94
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A semiconductor light-emitting element comprising a monocrystal substrate; a buffer layer formed directly on the monocrystal substrate and comprising a monocrystal Al_x Ga_1-x N layer (0<x<1); and element-forming layer formed on the buffer layer and comprising Al_x Ga_y In_1-x-y N (0≦x+Y≦1, 0≦x, Y≦1). The half-value width of an X-ray rocking curve of the buffer layer should preferably be 5 minutes or less, more preferably 90 seconds or less.

Claims

1. A semiconductor light-emitting element comprising:

a monocrystal substrate;

a buffer layer formed directly on said monocrystal substrate and comprising a monocrystal Al_x Ga_1-x N (0<

x≦

1) layer having a half-value width of an X-ray rocking curve falling within a range of 5 minutes or less, said buffer layer being formed at a high first temperature; and

an element-forming layer formed on said buffer layer and comprising Al_x Ga_y In_1-x-y N (0≦

x+y≦

1, 0≦

x, y≦

1), said element-forming layer being formed at a second temperature which is lower than said high first temperature.

2. The semiconductor light-emitting element according to claim 1, wherein a half-value width of an X-ray rocking curve of said buffer layer is 90 seconds or less.

3. The semiconductor light-emitting element according to claim 1, wherein said element-forming layer comprises a heterojunction structure.

4. The semiconductor light-emitting element according to claim 3, wherein said heterojunction structure comprises:

a first confinement layer constituted by Al_p Ga_1-p N (0<

p≦

1);

an active layer formed on said first confinement layer and constituted by a compound semiconductor selected from the group consisting of GaN, GaInN, AlGaN and AlGaInN; and

a second confinement layer formed on said active layer and constituted by Al_q Ga_1-q N (0<

q≦

1).

5. The semiconductor light-emitting element according to claim 4, wherein said first confinement layer has a film thickness of more than 0.3 μ

m and the Al molar fraction "p" is in a range of 0.25<

p≦

1.

6. The semiconductor light-emitting element according to claim 1, wherein said buffer layer has a film thickness falling in the range of from 20 nm to 0.3 μ

m.

7. The semiconductor light-emitting element according to claim 1, wherein said monocrystal substrate is formed of sapphire or SiC.

8. The semiconductor light-emitting element according to claim 7, wherein said monocrystal substrate is formed of sapphire and the Al molar fraction "x" is in a range of 0.2<

x<

1.

9. The semiconductor light-emitting element according to claim 1, wherein said element-forming layer comprises a heterojunction structure, said heterojunction structure being constituted by:

a first confinement layer constituted by Al_p Ga_1-p N (0<

p≦

1);

an active layer formed on said first confinement layer and constituted by a compound semiconductor selected from the group consisting of GaN, GaInN, AlGaN and AlGaInN; and

a second confinement layer formed on said active layer and constituted by Al_q Ga_1-q N (0<

q≦

1).

10. A semiconductor light-emitting element comprising:

a sapphire substrate;

a buffer layer formed directly on said sapphire substrate and comprising a monocrystal Al_x Ga_1-x N (0<

x≦

1) layer having a half-value width of an X-ray rocking curve falling within a range of 90 seconds or less, said buffer layer being formed at a high first temperature; and

a double heterojunction structure formed on said buffer layer, said double heterojunction structure being formed at a second temperature which is lower than said high first temperature;

said double heterojunction structure being constituted by;

a first confinement layer constituted by Al_p Ga_1-p N (0<

p≦

1);

an active layer formed on said first confinement layer and constituted by a compound semiconductor selected from the group consisting of GaN, GaInN, AlGaN and AlGaInN; and

a second confinement layer formed on said active layer and constituted by Al_q Ga_1-q N (0<

q≦

1).

11. The semiconductor light-emitting element according to claim 10, wherein said buffer layer has a film thickness falling in the range of from 20 nm to 0.3 μ

m.

12. The semiconductor light-emitting element according to claim 10, wherein the Al molar fraction "x" of said buffer layer is in a range of 0.2<

x<

1.