Method for Producing an Area having Reduced Electrical Conductivity Within a Semiconductor Layer and Optoelectronic Semiconductor Element

• US 20090008751A1
• Filed: 04/25/2005
• Published: 01/08/2009
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Wirth, Ralph, Stein, Wilhelm, Walter, Robert, Illek, Stefan
• Granted Patent: US 8,293,553 B2
• Time in Patent Office: Days
• US Class Current: 257/632
• CPC Class Codes: H01L 21/02461 Phosphides
• CPC Class Codes: H01L 21/02463 Arsenides
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02573 Conductivity type
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 21/7605 between components manufactured in an active substrate comprising AIII BV compounds
• CPC Class Codes: H01L 33/0062 for devices with an active region comprising only III-V compounds
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

In a method for producing at least at least one area (8) with reduced electrical conductivity within an electrically conductive III-V semiconductor layer (3), a ZnO layer (1) is applied to the area (8) of the semiconductor layer (3) and subsequently annealed at a temperature preferably between 300° C. and 500° C. The ZnO layer (1) is preferably deposited on the III-V semiconductor layer (3) at a temperature of less than 150° C., preferably at a temperature greater than or equal to 25° C. and less than or equal to 120° C. The area (8) with reduced electrical conductivity is preferably located in a radiation emitting optoelectronic device between the active zone (4) and a connecting contact (7) in order to reduce current injection into the areas of the active zone (4) located opposite to the connecting contact (7).

Claims

1. A method for producing at least one area having reduced electrical conductivity within an electrically conductive III-V semiconductor layer, comprising:

applying a ZnO layer on the area of the semiconductor layer; and

subsequently annealing.

2. The method of claim 1, wherein the ZnO layer is deposited on the III-V semiconductor layer at a temperature of less than 150°

C.

3. The method according to claim 1, wherein the deposition of the ZnO layer is performed by sputtering.

4. The method according to claim 1, wherein the ZnO layer is structured before annealing.

5. The method according to claim 1, wherein the annealing is performed at a temperature between 300°

C. and 500°

C.

6. The method according to claim 1, wherein the ZnO layer is doped with Al.

7. The method according to claim 1, wherein the III-V semiconductor layer comprises In_1-x-yGa_xAl_yP with 0≦

x+y≦

1, 0≦

x≦

1, 0≦

y≦

1 or Al_1-xGa_xAs with 0≦

x≦

1.

8. The method according to claim 1 wherein the III-V semiconductor layer is p-doped.

9. The method according to claim 1, wherein the electrical conductivity of the area of the III-V semiconductor layer is reduced by at least a factor of 2.

10. The method according to claim 1, wherein the III-V semiconductor layer is contained in an optoelectronic device.

11. The method according to claim 10, wherein the optoelectronic device contains a radiation emitting active zone and the current flow through subareas of active zone is reduced by the area having reduced electrical conductivity.

12. The method according to claim 11, wherein the area having reduced electrical conductivity is positioned between an electrical connecting contact of the optoelectronic device and the active zone.

13. The method according to claim 1, claims, wherein the ZnO layer is removed after the annealing.

14. The method according to claim 1, wherein the first ZnO layer is deposited on a first area of the semiconductor layer, and a second ZnO layer is deposited on a second area of the semiconductor layer, with the deposition temperature of the second ZnO layer increased relative to the deposition temperature of the first ZnO layer such that the conductivity of the second area of semiconductor layer is at least less reduced than the conductivity of the first area of semiconductor layer during annealing.

15. The method according to claim 14, wherein the second ZnO layer is deposited at a temperature greater than 150°

C.

16. An optoelectronic semiconductor device with a III-V semiconductor layer that has at least one area having reduced electrical conductivity produced using the method of claim 1.

25. The method of claim 1, wherein the ZnO layer is deposited on the III-V semiconductor layer at a temperature of between 25°

C. inclusive and 120°

C. inclusive.

26. The method according to claim 1, wherein the ZnO layer is doped with a concentration of less than or equal to 3%.

17. An optoelectronic semiconductor device with a III-V semiconductor layer that is covered with a ZnO layer in at least one area, wherein the conductivity of the semiconductor layer in the first area covered by the ZnO layer is lower than in the laterally adjacent areas of III-V semiconductor layer.

18. The optoelectronic semiconductor device according to claim 17, wherein the electrical conductivity of the first area of semiconductor layer is reduced by at least a factor of 2, relative to the laterally adjacent areas of III-V semiconductor layer.

19. The optoelectronic semiconductor according to claim 17, wherein the ZnO layer is doped with Al.

20. The optoelectronic semiconductor device according to claim 17, wherein the semiconductor layer comprises In_1-x-yGa_xAl_yP with 0≦

x+y≦

1, 0≦

x≦

1, 0≦

y≦

1 or Al_1-xGa_xAs with 0≦

x≦

1.

21. The optoelectronic semiconductor device according to claim 17, wherein a second ZnO layer is deposited on a second area of semiconductor layer and the conductivity of the second area of the semiconductor layer is greater than the conductivity of the first area.

22. The optoelectronic semiconductor device according to claim 21, wherein the first ZnO layer and the second ZnO layer are adjacent to one another and located between the III-V semiconductor layer and a connecting contact of the optoelectronic device.

23. The optoelectronic semiconductor device according to claim 22, wherein the first ZnO layer and the second ZnO layer jointly form a current dispersing layer.

24. An optoelectronic semiconductor device according to claim 17, that contains a radiation emitting active zone and in which the area with reduced electrical conductivity is located between an electrical connecting contact of the optoelectronic device and the active zone.