Semiconductor substrate of GaAs and semiconductor device

• US 7,875,961 B2
• Filed: 11/19/2009
• Issued: 01/25/2011
• Est. Priority Date: 09/30/2005
• Status: Expired due to Fees

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Heidborn, Peter, Kugler, Siegmar, Linder, Norbert, Grönninger, Günther, Streubel, Klaus
• Primary Examiner(s): Cao; Phat X
• Assistant Examiner(s): VIEIRA, DIANA C
• Application Number:
  US12/621,854
• Publication Number:
  US 20100065890A1
• Time in Patent Office: 432 Days
• Field of Search: 257/185, 257/657, 257/655, 257/E33.003, 257/E21.002
• US Class Current: 257/657
• 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, of GaAs with a semiconductor layer sequence applied on top of the substrate. The semiconductor layer sequence comprises a plurality of semiconductor layers of Al_1-yGa_yAs_1-xP_x with 0≦x≦1 and 0≦y≦1. A number of the semiconductor layers respectively comprising 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. Two semiconductor layers directly preceding the uppermost semiconductor layer of the semiconductor layer sequence have a smaller lattice constant than the uppermost layer.

Claims

1. A semiconductor substrate of GaAs with a semiconductor layer sequence applied on top of the substrate, the semiconductor layer sequence comprising a plurality of semiconductor layers of Al_1-yGa_yAs_1-xP_x with 0≦

x≦

1 and 0≦

y≦

1, a number of the semiconductor layers respectively comprising 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, wherein two semiconductor layers directly preceding the uppermost semiconductor layer of the semiconductor layer sequence have a smaller lattice constant than the uppermost layer.

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

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

0.15.

4. The semiconductor substrate as claimed in claim 1, wherein, for the aluminum component 1-y in the semiconductor layer sequence, 1-y=0.

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

m or less.

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

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

8. The semiconductor substrate as claimed in claim 7, wherein the uppermost semiconductor layer of the semiconductor layer sequence is relaxed.

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

10. The semiconductor device as claimed in claim 9, wherein the semiconductor device is an optoelectronic device.

11. The semiconductor device as claimed in claim 10, wherein the optoelectronic device is a luminescence diode or a semiconductor laser.

12. The semiconductor device as claimed in claim 10, wherein the optoelectronic device contains a radiation-detecting or radiation-emitting layer.

13. The semiconductor device as claimed in claim 12, wherein the radiation-detecting or radiation-emitting layer contains In_xAl_yGa_1-x-yP with 0≦

x<

0.5, 0≦

y≦

1 and x+y≦

1.

14. The semiconductor device as claimed in claim 12, wherein the radiation-detecting or radiation-emitting layer contains ZnSSe or ZnMgSSe.

15. The semiconductor device as claimed in claim 12, wherein the radiation-detecting or radiation-emitting layer contains GaAsN or InGaAsN.

16. The semiconductor device as claimed in claim 12, 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.