Semiconductor substrate of GaAs and semiconductor device

• US 20070090396A1
• Filed: 09/28/2006
• Published: 04/26/2007
• Est. Priority Date: 09/30/2005
• Status: Abandoned Application

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Heidborn, Peter, Streubel, Klaus, Kugler, Siegmar, Linder, Norbert, Gronninger, Gunther
• Application Number:
  US11/541,089
• Publication Number:
  US 20070090396A1
• Time in Patent Office: Days
• US Class Current: 257/185
• CPC Class Codes: H01L 21/02395 Arsenides
• CPC Class Codes: H01L 21/02461 Phosphides
• CPC Class Codes: H01L 21/02463 Arsenides
• CPC Class Codes: H01L 21/02505 consisting of more than two layers
• CPC Class Codes: H01L 21/02507 Alternating layers, e.g. superlattice
• CPC Class Codes: H01L 21/02543 Phosphides
• CPC Class Codes: H01L 21/02546 Arsenides
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table

Abstract

A semiconductor substrate (1) of GaAs with a semiconductor layer sequence (2) applied on top. The semiconductor layer sequence (2) contains a plurality of semiconductor layers (3, 4, 5, 6, 7) of Al_1−yGa_yAs_1−xPx with 0≦x≦1 and 0≦y≦1, the phosphorus component x in a number of the semiconductor layers respectively being greater than in a neighboring semiconductor layer lying thereunder in the direction of growth. Such a semiconductor substrate may be advantageously used as a quasi-substrate substrate (8) for growing further semiconductor layers (28) which have a smaller lattice constant than GaAs.

Claims

1. A semiconductor substrate of GaAs with a semiconductor layer sequence applied on top, wherein the semiconductor layer sequence contains a plurality of semiconductor layers of Al₁₋

yGa_yAs<sub>1−

x</sub>P_x with 0≦

x≦

1 and 0≦

y≦

1, a number of the semiconductor layers respectively having a phosphorus component x which is greater than in a neighboring semiconductor layer lying thereunder in the direction of growth of the semiconductor layer sequence.

2. The semiconductor substrate as claimed in claim 1, wherein the phosphorus component x in at least 2 semiconductor layers of the semiconductor layer sequence is greater than in a neighboring semiconductor layer lying thereunder in the direction of growth of the semiconductor layer sequence.

3. The semiconductor substrate as claimed in claim 1, wherein the phosphorus component x increases stage by stage in a number of successive semiconductor layers of the semiconductor layer sequence.

4. The semiconductor substrate as claimed in claim 3, wherein the phosphorus component x increases stage by stage in at least 3 successive semiconductor layers of the semiconductor layer sequence.

5. The semiconductor substrate as claimed in claim 1, wherein the semiconductor layer sequence includes a superlattice structure comprising alternating first semiconductor layers and second semiconductor layers, the first semiconductor layers containing a phosphorus component x₁≧

0 and the second semiconductor layers containing a phosphorus component x₂≧

0 with x₁≠

x₂.

6. The semiconductor substrate as claimed in claim 1, for the phosphorus component x in the uppermost semiconductor layer of the semiconductor layer sequence, x≧

0.15.

7. The semiconductor substrate as claimed in claim 1, wherein, for the aluminum component 1−

y in the semiconductor layer sequence, 1−

y=0.

8. The semiconductor substrate as claimed in claim 1, wherein the overall thickness of the semiconductor layer sequence is 10 μ

m or less.

9. The semiconductor substrate as claimed in claim 1, wherein the semiconductor layers have a thickness of between 100 nm and 1000 nm, inclusive.

10. The semiconductor substrate as claimed in claim 1, wherein the uppermost semiconductor layer of the semiconductor layer sequence has a smaller lattice constant than the GaAs substrate.

11. The semiconductor substrate as claimed in claim 1, wherein the uppermost semiconductor layer of the semiconductor layer sequence has a smaller lattice constant than at least one of the preceding semiconductor layers.

12. The semiconductor substrate as claimed in claim 11, wherein the uppermost semiconductor layer of the semiconductor layer sequence has a smaller lattice constant than the two semiconductor layers preceding it.

13. The semiconductor substrate as claimed in claim 1, wherein at least one semiconductor layer of the semiconductor layer sequence is relaxed.

14. The semiconductor substrate as claimed in claim 13, wherein the uppermost semiconductor layer of the semiconductor layer sequence is relaxed.

15. A semiconductor device, wherein the semiconductor contains a GaAs substrate with a semiconductor layer sequence as claimed in claim 1 applied on top.

16. The semiconductor device as claimed in claim 15, wherein the semiconductor device is an optoelectronic device.

17. The semiconductor device as claimed in claim 16, wherein the optoelectronic device is a luminescence diode or a semiconductor laser.

18. The semiconductor device as claimed in claim 16, wherein the optoelectronic device contains a radiation-detecting or radiation-emitting layer.

19. The semiconductor device as claimed in claim 18, wherein the radiation-detecting or radiation-emitting layer contains In_xAl_yGa₁₋

x−

yP with 0≦

x<

0.5, 0≦

y≦

1 and x+y≦

1.

20. The semiconductor device as claimed in claim 18, wherein the radiation-detecting or radiation-emitting layer contains ZnSSe or ZnMgSSe.

21. The semiconductor device as claimed in claim 18, wherein the radiation-detecting or radiation-emitting layer contains GaAsN or InGaAsN.

22. The semiconductor device as claimed in claim 18, wherein the radiation-detecting or radiation-emitting layer is included in a further semiconductor layer sequence, which is epitaxially grown on the semiconductor layer sequence.