Semiconductor device and fabrication method

Patent metadata

Field	Value
Publication number	US-9793686-B2
Application number	US-201615099906-A
Country	US
Kind code	B2
Filing date	Apr 15, 2016
Priority date	Aug 1, 2012
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A semiconductor device comprising a silicon substrate on which is grown a <100 nm thick epilayer of AlAs or related compound, followed by a compound semiconductor other than GaN buffer layer. Further III-V compound semiconductor structures can be epitaxially grown on top. The AlAs epilayer reduces the formation and propagation of defects from the interface with the silicon, and so can improve the performance of an active structure grown on top.

First claim

The invention claimed is:

1. A semiconductor laser device comprising:
a silicon substrate;
an epilayer formed on the substrate;
a dot-in-well (DWELL) structure comprising multiple layers, each of the multiple layers comprising GaAs and an InGaAs alloy; and
at least one layer of III-V compound, other than GaN, on the epilayer, wherein the epilayer comprises a compound of the formula:
Al 1−x [X] x As

wherein:
X is at least one group III element other than Al;
x is greater than or equal to 0; and
x is less than or equal to 0.5.

2. The semiconductor laser device of claim 1 , wherein the mean thickness of the epilayer is less than 100 nm.

3. The semiconductor laser device of claim 1 , wherein the mean thickness of the epilayer is less than 20 nm.

4. The semiconductor laser device of claim 1 , wherein the mean thickness of the epilayer is less than 10 nm.

5. The semiconductor laser device of claim 1 , wherein a first of the III-V compound layers on the epilayer is one of a GaAs layer, an InP layer or a GaSb layer.

6. The semiconductor laser device of claim 1 , wherein X is Ga.

7. The semiconductor laser device of claim 1 , wherein the epilayer is AlAs.

8. The semiconductor laser device of claim 1 , wherein the III-V compound layer has a zinc blende crystal structure.

9. A quantum dot laser comprising:
a semiconductor laser device comprising:
a silicon substrate;
an epilayer formed on the silicon substrate; and
at least one layer of III-V compound, other than GaN, on the epilayer, wherein the epilayer comprises a compound of the formula:
Al 1−x [X] x As

wherein:
X is at least one group III element other than Al;
x is greater than or equal to 0; and
x is less than or equal to 0.5.

10. The quantum dot laser of claim 9 , wherein the lasing wavelength is in the range of from 1250 nm to 1350 nm.

11. The quantum dot laser of claim 9 , comprising InAs/GaAs quantum dot structures.

12. The quantum dot laser of claim 9 , wherein the mean thickness of the epilayer is less than 10 nm.

13. The quantum dot laser of claim 9 , wherein X is Ga.

14. The quantum dot laser of claim 9 , wherein the epilayer is AlAs.

15. The quantum dot laser of claim 9 , wherein the at least one layer of III-V compound has a zinc blende crystal structure.

16. A method of fabricating a semiconductor laser device, said method comprising:
providing a silicon substrate;
epitaxially growing an epilayer on the substrate;
growing a dot-in-well (DWELL) structure by growing multiple layers, each of the multiple layers comprising GaAs and an InGaAs alloy; and
epitaxially growing at least one layer of III-V compound, other than GaN, on the epilayer, wherein the epilayer comprises a compound of the formula:
Al 1−x [X] x As

wherein:
X is at least one group III element other than Al;
x is greater than or equal to 0; and
x is less than or equal to 0.5.

17. The method of claim 16 , comprising growing the epilayer to have a mean thickness of less than 100 nm.

18. The method of claim 16 , comprising growing the epilayer at a temperature below 500° C.

19. The method to of claim 16 , wherein the epilayer is AlAs.

20. The semiconductor laser device of claim 1 , wherein the epilayer has a mean thickness of at least 2.5 nm.

21. The quantum dot laser of claim 9 , wherein the epilayer of the semiconductor laser device has a mean thickness of at least 2.5 nm.

22. The method of claim 16 , wherein the epilayer is epitaxially grown to have a mean thickness of at least 2.5 nm.

23. The quantum dot laser of claim 9 , wherein the lasing wavelength is in the range of from 1100 nm to 1350 nm.

Assignees

• Ucl Business Plc

Inventors

• Liu Huiyun
• Lee Andrew David
• Seeds Alwyn John

Classifications

• H10P14/3602

  In-situ cleaning · CPC title

• H10P14/3422

  Antimonides · CPC title

• H10P14/3414

  being group IIIA-VIA materials · CPC title

• H10P14/3252

  Alternating layers, e.g. superlattice · CPC title

• H10P14/3221

  Arsenides · CPC title