INFRARED DETECTING DEVICE

• US 20200028020A1
• Filed: 01/08/2019
• Published: 01/23/2020
• Est. Priority Date: 01/18/2018
• Status: Active Grant

• Current Assignee: Asahi Kasei Microdevices Corporation (Asahi Kasei Corporation)
• Original Assignee: Asahi Kasei Microdevices Corporation (Asahi Kasei Corporation)
• Inventors: SAKURAI, Yoshiki, MOROHARA, Osamu, FUJITA, Hiromi
• Granted Patent: US 10,644,185 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 31/03046 including ternary or quaternary compounds, e.g. GaAlAs, InGaAs, InGaAsP
• CPC Class Codes: H01L 31/035236 Superlattices; Multiple quantum well structures
• CPC Class Codes: H01L 31/105 the potential barrier being of the PIN type
• CPC Class Codes: H01L 31/109 the potential barrier being of the PN heterojunction type

Abstract

Provided is an infrared detecting device with high SNR. The infrared detecting device includes: a semiconductor substrate; a first compound semiconductor layer; a light receiving layer formed on the first compound semiconductor layer and containing at least In and Sb and having a predetermined range(s) of Al or Al and Ga proportion(s); a third compound semiconductor layer; and a second compound semiconductor layer containing at least In, Al, and Sb and having a predetermined range(s) of Al or Al and Ga proportion(s), in which the first compound semiconductor layer includes, in the stated order, a first A layer, a first B layer, and a first C layer, each containing at least In and Sb and having a predetermined range(s) of Al or Al and Ga proportion(s), and the proportion(s) of the Al composition or the Al composition and the Ga composition of each layer satisfy a predetermined relation(s).

Claims

1. An infrared detecting device comprising:

a semiconductor substrate;

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

a light receiving layer formed on the first compound semiconductor layer and containing at least In and Sb, where the light receiving layer has an Al composition at a proportion of n_light [%] in all group III elements in the light receiving layer where 0≤

n_light<

18;

a third compound semiconductor layer formed on the light receiving layer and having a second conductivity type; and

a second compound semiconductor layer formed in at least one of regions between the light receiving layer and the third compound semiconductor layer or between the first compound semiconductor layer and the light receiving layer, containing at least In, Al, and Sb, having an Al composition at a proportion of n₂ [%] in all group III elements in the second compound semiconductor layer where 0<

n₂<

100, and having a film thickness of m₂ [nm] where m₂>

2, wherein the first compound semiconductor layer comprises, in the stated order;

a first A layer containing at least In and Sb and having an Al

composition at a proportion of n_1A [%] in all group III elements in the first A layer where 0≤

n_1A<

18;

a first B layer containing at least In and Sb, having an Al composition at a proportion of n_1B [%] in all group III elements in the first B layer where 0≤

n_1B<

100, and having a film thickness of m_1B [nm]; and

a first C layer containing at least In and Sb and having an Al composition at a proportion of n_1C [%] in all group III elements in the first C layer where 0≤

n_1C<

18,

where n_1A, n_1B, n_1C, n₂, n_light, m_1B, and m₂ satisfy the following relations;

|n₂−

n_light|×

m₂≤

|n_1B−

n_1A|×

m_1B;

n_1B>

n_1A and n_1B>

n_1C, or n_1B<

n_1A and n_1B<

n_1C; and

n₂>

n_light+5.

2. The infrared detecting device according to claim 1, wherein n_light, n_1A, and n_1C satisfy the following relations:

8≤

n_light≤

12;

8≤

n_1A≤

12; and

8≤

n_1C≤

12.

3. The infrared detecting device according to claim 1, wherein n_light, n_1A, and n_1C satisfy the following relations:

4≤

n_light≤

8;

4≤

n_1A≤

8; and

4≤

n_1C≤

8.

4. The infrared detecting device according to claim 1, wherein n₂, n_light, and m₂ satisfy the following relation:

|n₂−

n_light|×

m₂≤

572.

5. The infrared detecting device according to claim 1, wherein n_light and n₂ satisfy the following relation:

n₂>

n_light+7.

6. The infrared detecting device according to claim 1, wherein m₂ satisfies the following relation:

m₂≥

4.

7. The infrared detecting device according to claim 1, wherein the first conductivity type is n type and the second conductivity type is p type.

8. The infrared detecting device according to claim 1, wherein infrared rays incident from the semiconductor substrate side are detected.

9. The infrared detecting device according to claim 1, wherein n_1A, n_1C, and n_light are the same.

10. The infrared detecting device according to claim 1, wherein the second compound semiconductor layer is formed in both of regions between the light receiving layer and the third compound semiconductor layer and between the first compound semiconductor layer and the light receiving layer.

11. An infrared detecting device comprising:

a semiconductor substrate;

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

a light receiving layer formed on the first compound semiconductor layer, containing at least In and Sb, and having an Al composition at a proportion of n_{Al light} [%] in all group III elements in the light receiving layer and a Ga composition at a proportion of n_{Ga light} [%] in all group III elements in the light receiving layer, where a sum of the proportions n_{Al light} and n_{Ga light} satisfies a relation of 0<

n_{Al light}+n_{Ga light}<

18;

a third compound semiconductor layer formed on the light receiving layer and having a second conductivity type; and

a second compound semiconductor layer formed in at least one of regions between the light receiving layer and the third compound semiconductor layer or between the first compound semiconductor layer and the light receiving layer, containing at least In, Al, and Sb, having an Al composition at a proportion of n_Al2 [%] in all group III elements in the second compound semiconductor layer where 0≤

n_Al2<

100 and a Ga composition at a proportion of n_Ga2 [%] in all group III elements in the second compound semiconductor layer where 0≤

n_Ga2<

100, and having a film thickness of m₂ [nm] where m₂>

2,

wherein the first compound semiconductor layer comprises, in the stated order;

a first A layer containing at least In and Sb and having an Al composition at a proportion of n_Al1A [%] in all group III elements in the first A layer and a Ga composition at a proportion of n_Ga1A [%] in all group III elements in the first A layer, where a sum of the proportions n_Al1A and n_Ga1A satisfies a relation of 0<

n_Al1A+n_Ga1A<

18;

a first B layer containing at least In and Sb, having an Al composition at a proportion of n_Al1B [%] in all group III elements in the first B layer and a Ga composition at a proportion of n_Ga1B [%] in all group III elements in the first B layer, where a sum of the proportions n_Al1B and n_Ga1B satisfies a relation of 0<

n_Al1B+n_Ga1B<

100, and having a film thickness of m_1B [nm]; and

a first C layer containing at least In and Sb and having an Al composition at a proportion of n_Al1C [%] in all group III elements in the first C layer and a Ga composition at a proportion of n_Ga1C [%] in all group III elements in the first C layer, where a sum of the proportions n_Al1C and n_Ga1C satisfies a relation of 0<

n_Al1C+n_Ga1C<

18,

where n_Al1A, n_Ga1A, n_Al1B, n_Ga1B, n_Al1C, n_Ga1C, n_Al2, n_Ga2, n_{Al light}, n_{Ga light}, m_1B, and m₂ satisfy the following relations;

|n_Al2+n_Ga2−

(n_{Al light}+n_{Ga light})|×

m₂+n_Ga1B−

(n_Al1A+n_Ga1A)|×

m_1B;

n_Al1B+n_Ga1B>

n_Al1A+n_Ga1A and n_Al1B+n_Ga1B>

n_Al1C+n_Ga1C, or n_Al1B+n_Ga1B<

n_Al1A+n_Ga1A and n_Al1B+n_Ga1B<

n_Al1C+n_Ga1C;

n_Al2+n_Ga2>

n_{Al light}+n_{Ga light}+5;

0<

n_Ga2/(n_Al2+n_Ga2)≤

1;

0<

n_{Ga light}/(n_{Al light}+n_{Ga light)≤}

1;

0<

n_Ga1A/(n_Al1A+n_Ga1A)≤

1;

0<

n_Ga1B/(n_Al1B+n_Ga1B)≤

1; and

0<

n_Ga1C/(n_Al1C+n_Ga1C)≤

1.

12. The infrared detecting device according to claim 11, wherein n_{Al light}, n_{Ga light}, n_Al1A, n_Ga1A, n_Al1C, and n_Ga1C satisfy the following relations:

8≤

n_{Al light}+n_{Ga light}<

12;

8≤

n_Al1A+n_Ga1A≤

12; and

8≤

n_Al1C+n_Ga1C≤

12.

13. The infrared detecting device according to claim 11, wherein n_{Al light}, n_{Ga light}, n_Al1A, n_Ga1A, n_Al1C, and n_Ga1C satisfy the following relations:

4<

n_{Al light}+n_{Ga light}<

8;

4n_Al1A+n_Ga1A≤

8; and

4n_Al1C+n_Ga1C≤

8.

14. The infrared detecting device according to claim 11, wherein n_Al2, n_Ga2, n_{Al light}, n_{Ga light}, and m₂ satisfy the following relation:

|n_Al2+n_Ga2−

(n_{Al light}+n_{Ga light})×

m₂≤

572.

15. The infrared detecting device according to claim 11, wherein n_{Al light}, n_{Ga light}, n_Al2, and n_Ga2 satisfy the following relation:

n_Al2+n_Ga2>

n_{Al light}+n_{Ga light}+7.

16. The infrared detecting device according to claim 11, wherein m₂ satisfies the following relation:

m2>

_4.

17. The infrared detecting device according to claim 11, wherein the first conductivity type is n type and the second conductivity type is p type.

18. The infrared detecting device according to claim 11, wherein infrared rays incident from the semiconductor substrate side are detected.

19. The infrared detecting device according to claim 11, wherein n_Al1A, n_AlC, and n_{Al light} are the same, and n_Ga1A, n_Ga1C, and n_{Ga light} are also the same.

20. The infrared detecting device according to claim 11, wherein the second compound semiconductor layer is formed in both of regions between the light receiving layer and the third compound semiconductor layer and between the first compound semiconductor layer and the light receiving layer.