Infrared light emitting device

• US 10,573,782 B2
• Filed: 12/13/2018
• Issued: 02/25/2020
• Est. Priority Date: 12/21/2017
• Status: Active Grant

• Current Assignee: Asahi Kasei Microdevices Corporation (Asahi Kasei Corporation)
• Original Assignee: Asahi Kasei Microdevices Corporation (Asahi Kasei Corporation)
• Inventors: Morohara, Osamu, Fujita, Hiromi, Geka, Hirotaka
• Primary Examiner(s): Sullivan, Caleen O
• Application Number:
  US16/218,810
• Publication Number:
  US 20190198713A1
• Time in Patent Office: 439 Days
• Field of Search: 257 79
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/305 characterised by the doping materials

Abstract

Disclosed is an infrared light emitting device including: a semiconductor substrate; a first layer formed on the semiconductor substrate and having a first conductivity type; a light emitting layer formed on the first layer; and a second layer formed on the light emitting layer and having a second conductivity type, wherein the first layer includes, in the stated order: a layer containing Al_x(1)In_1−x(1)Sb; a layer having a film thickness t_y(1) in nanometers and containing Al_y(1)In_1−y(1)Sb; and a layer containing Al_x(2)In_1−x(2)Sb, where t_y(1), x(1), x(2), and y(1) satisfy the following relations: for j=1, 2, 0<t_y(1)≤2360×(y(1)−x(j))−240 (0.11≤y(1)−x(j)≤0.19), 0<t_y(1)≤−1215×(y(1)−x(j))+427 (0.19<y(1)−x(j)≤0.33), and 0<x(j)<0.18.

Claims

1. An infrared light emitting device comprising:

a semiconductor substrate;

a first layer formed on the semiconductor substrate and having a first conductivity type;

a light emitting layer formed on the first layer; and

a second layer formed on the light emitting layer and having a second conductivity type, wherein

the first layer comprises, in the stated order;

a layer containing Al_x(1)In<sub>1−

x(1)</sub>Sb;

a layer having a film thickness t_y(1) in nanometers and containing Al_y(1)In<sub>1−

y(1)</sub>Sb; and

a layer containing Al_x(2)In<sub>1−

x(2)</sub>Sb,

where t_y(1), x(1), x(2), and y(1) satisfy the following relations;

0<

t_y(1)≤

2360×

(y(1)−

x(1))−

240(0.1≤

y(1)−

x(1)≤

0.19),

0<

t_y(1)≤

−

1215×

(y(1)−

x(1))+427(0.19<

y(1)−

x(1)≤

0.33),

0<

t_y(1)≤

2360×

(y(1)−

x(2))−

240(0.11≤

y(1)−

x(2)≤

0.19),

0<

t_y(1)≤

−

1215×

(y(1)−

x(2))+427(0.19<

y(1)−

x(2)≤

0.33),

0<

x(1)<

0.18, and

0<

x(2)<

0.18.

2. The infrared light emitting device according to claim 1, wherein t_y(1), x(1), x(2), and y(1) satisfy the following relations:

0<

t_y(1)≤

6901×

(y(1)−

x(1))−

1087(0.16≤

y(1)−

x(1)≤

0.19),

0<

t_y(1)≤

−

2673×

(y(1)−

x(1))+699(0.19<

y(1)−

x(1)≤

0.25),

0<

t_y(1)≤

6901×

(y(1)−

x(2))−

1087(0.16≤

y(1)−

x(2)≤

0.19), and

0<

t_y(1)≤

−

2673×

(y(1)−

x(2))+699(0.19<

y(1)−

x(2)≤

0.25).

3. The infrared light emitting device according to claim 1, wherein t_y(1), x(1), x(2), and y(1) satisfy the following relations:

0<

t_y(1)≤

1993×

(y(1)−

x(1))−

242(0.13≤

y(1)−

x(1)≤

0.19),

0<

t_y(1)≤

−

1040×

(y(1)−

x(1))+324(0.19<

y(1)−

x(1)≤

0.29),

0<

t_y(1)≤

1993×

(y(1)−

x(2))−

242(0.13≤

y(1)−

x(2)≤

0.19), and

0<

t_y(1)≤

−

1040×

(y(1)−

x(2))+324(0.19<

y(1)×

x(2)≤

0.29).

4. The infrared light emitting device according to claim 1, wherein t_y(1), m, x(1), x(2), and y(1) satisfy the following relations:

0<

t_y(1)≤

3067×

(y(1)−

x(1))−

472(0.16≤

y(1)−

x(1)≤

0.19),

0<

t_y(1)≤

−

1188×

(y(1)−

x(1))+322(0.19<

y(1)−

x(1)≤

0.25),

0<

t_y(1)≤

3067×

(y(1)−

x(2))−

472(0.16≤

y(1)−

x(2)≤

0.19), and

0<

t_y(1)≤

−

1188×

(y(1)−

x(2))+322(0.19<

y(1)−

x(2)≤

0.25).

5. The infrared light emitting device according to claim 1, wherein for an integer i from 1 to n (2 n 6), the first layer comprises:

a layered structure in which a layer containing Al_x(i)In<sub>1−

x(i)</sub>Sb and a layer having a film thickness t_y(i) in nanometers and containing Al_y(i)In<sub>1−

y(i)</sub>Sb are sequentially stacked on top of one another in the stated order in n layers; and

a layer containing Al_x(n+1)In<sub>1−

x(n+1)</sub>Sb directly on the layer having a film thickness t_y(n) in nanometers and containing Al_y(n)In<sub>1−

y(n)</sub>Sb, where t_y(i), x(i), x(i+1), and y(i) satisfy the following relations;

0<

t_y(i)≤

2360×

(y(i)−

x(i))−

240(0.11≤

y(i)−

x(i)≤

0.19),

0<

t_y(i)≤

−

1215×

(y(i)−

x(i))+427(0.19<

y(i)−

x(i)≤

0.33),

0<

t_y(i)≤

2360×

(y(i)−

x(i+1))−

240(0.11≤

y(i)−

x(i+1)≤

0.19),

0<

t_y(i)≤

−

1215×

(y(i)−

x(i+1))+427(0.19<

y(i)−

x(i+1)≤

0.33),

0<

x(i)<

0.18, and

0<

x(i+1)<

0.18.

6. The infrared light emitting device according to claim 5, wherein t_y(i), x(i), x(i+1), and y(i) satisfy the following relations:

0<

t_y(i)≤

6901×

(y(i)−

x(i))−

1087(0.16≤

y(i)−

x(i)≤

0.19),

0<

t_y(i)≤

−

2673×

(y(i)−

x(i))+699(0.19<

y(i)−

x(i)≤

0.25),

0<

t_y(i)≤

6901×

(y(i)−

x(i+1))−

1087(0.16≤

y(i)−

x(i+1)≤

0.19),

and

0<

t_y(i)≤

−

2673×

(y(i)−

x(i+1))+699(0.19<

y(i)−

x(i+1)≤

0.25).

7. The infrared light emitting device according to claim 5, wherein t_y(i), x(i), x(i+1), and y(i) satisfy the following relations:

0<

t_y(i)≤

1993×

(y(i)−

x(i))−

242(0.13≤

y(i)−

x(i)≤

0.19),

0<

t_y(i)≤

−

1040×

(y(i)−

x(i))+324(0.19<

y(i)−

x(i)≤

0.29),

0<

t_y(i)≤

1993×

(y(i)−

x(i+1))−

242(0.13≤

y(i)−

x(i+1)≤

0.19),

and

0<

t_y(i)≤

−

1040×

(y(i)−

x(i+1))+324(0.19<

y(i)−

x(i+1)≤

0.29).

8. The infrared light emitting device according to claim 5, wherein t_y(i), x(i), x(i+1), and y(i) satisfy the following relations:

0<

t_y(i)≤

3067×

(y(i)−

x(i))−

472(0.16≤

y(i)−

x(i)≤

0.19),

0<

t_y(i)≤

−

1188×

(y(i)−

x(i))+322(0.19<

y(i)−

x(i)≤

0.25),

0<

t_y(i)≤

3067×

(y(i)−

x(i+1))−

472(0.16≤

y(i)−

x(i+1)≤

0.19),

and

0<

t_y(i)≤

1188×

(y(i)−

x(i+1))+322(0.19<

y(i)−

x(i+1)≤

0.25).

9. The infrared light emitting device according to claim 1, wherein the first conductivity type is n type and the second conductivity type is p type.

10. The infrared light emitting device according to claim 1, wherein

the semiconductor substrate is a GaAs substrate, and

the first layer comprises a layer in contact with the GaAs substrate, wherein the layer is made of InSb.

11. The infrared light emitting device according to claim 1, wherein the light emitting layer contains Al_zIn₁₋

zSb (0<

z<

0.18).

12. The infrared light emitting device according to claim 1, wherein x(1) and x(2) satisfy the following relations:

0<

x(1)<

0.09, and

0<

x(2)<

0.09.

13. The infrared light emitting device according to claim 1, wherein the light emitting layer contains Al_zIn₁₋

zSb (0<

z<

0.09).

14. The infrared light emitting device according to claim 1, wherein at least one of the layer containing Al_x(1)In₁₋

x(1)Sb, the layer containing Al_y(1)In<sub>1−

y(1)</sub>Sb, or the layer containing Al_x(2)In<sub>1−

x(2)</sub>Sb further contains As at a proportion of 3% or less with respect to all V group elements.

15. The infrared light emitting device according to claim 1, wherein t_y(1) is not more than 6 times a critical film thickness.

16. The infrared light emitting device according to claim 1, wherein t_y(1) is not more than 100 nm.

17. The infrared light emitting device according to claim 1, wherein the light emitting layer has a line defect density of 3.0×

10⁸ [lines/cm²] or less.

18. An infrared light emitting device comprising:

a semiconductor substrate;

a first layer formed on the semiconductor substrate and having a first conductivity type;

a light emitting layer formed on the first layer; and

a second layer formed on the light emitting layer and having a second conductivity type, wherein

the first layer comprises, in the stated order;

a layer containing Al_x(1)Ga_p(1)In<sub>1−

x(1)−

p(1)</sub>Sb;

a layer having a film thickness t_y(1) in nanometers and containing Al_y(1)Ga_q(1)In<sub>1−

y(1)−

q(1)</sub>Sb; and

a layer containing Al_x(2)Ga_p(2)In<sub>1−

x(2)−

p(2)</sub>Sb,

where t_y(1), x(1), x(2), y(1), p(1), p(2), and q(1) satisfy the following relations;

0<

t_y(1)≤

2360×

(y(1)+q(1)−

x(1)−

p(1))−

240(0.11≤

y(1)+q(1)−

x(1)−

p(1)≤

0.19),

0<

t_y(1)≤

−

1215×

(y(1)+q(1)−

x(1)−

p(1))+427(0.19<

y(1)+q(1)−

x(1)−

p(1)≤

0.33),

0<

t_y(1)≤

2360×

(y(1)+q(1)−

x(2)−

p(2))−

240(0.11≤

y(1)+q(1)−

x(2)−

p(2)≤

0.19),

0<

t_y(1)≤

−

1215×

(y(1)+q(1)−

x(2)−

p(2))+427(0.19<

y(1)+q(1)−

x(2)≤

p(2)≤

0.33),

0<

x(1)+p(1)<

0.18,

0<

x(2)+p(2)<

0.18, and

0<

q(1)/(y(1)+q(1))≤

1.

19. The infrared light emitting device according to claim 18, wherein t_y(1), x(1), x(2), y(1), p(1), p(2), and q(1) satisfy the following relations:

0<

t_y(1)≤

1993×

(y(1)+q(1)−

x(1)−

p(1))−

242(0.13≤

y(1)+q(1)−

x(1)−

p(1)≤

0.19),

0<

t_y(1)≤

−

1040×

(y(1)+q(1)−

x(1)−

p(1))+324(0.19<

y(1)+q(1)−

x(1)≤

p(1)≤

0.29),

0<

t_y(1)≤

1993×

(y(1)+q(1)−

x(2)−

p(2))−

242(0.13≤

y(1)+q(1)−

x(2)−

p(2)≤

0.19), and

0<

t_y(1)≤

−

1040×

(y(1)+q(1)−

x(2)−

p(2))+324(0.19<

y(1)+q(1)−

x(2)−

p(2)≤

0.29).

20. The infrared light emitting device according to claim 18, wherein t_y(1), x(1), x(2), y(1), p(1), p(2), and q(1) satisfy the following relations:

0<

t_y(1)≤

3067×

(y(1)+q(1)−

x(1)−

p(1))−

472(0.16≤

y(1)+q(1)−

x(1)−

p(1)≤

0.19),

0<

t_y(1)≤

−

1188×

(y(1)+q(1)−

x(1)−

p(1))+322(0.19<

y(1)+q(1)−

x(1)−

p(1)−

0.25),

0<

t_y(1)≤

3067×

(y(1)+q(1)−

x(2)−

p(2))−

472(0.16≤

y(1)+q(1)−

x(2)−

p(2)≤

0.19), and

0<

t_y(1)≤

−

1188×

(y(1)+q(1)−

x(2)−

p(2))+322(0.19<

y(1)+q(1)−

x(2)−

p(2)≤

0.25).