Method for producing an area having reduced electrical conductivity within a semiconductor layer and optoelectronic semiconductor element

• US 8,293,553 B2
• Filed: 04/25/2005
• Issued: 10/23/2012
• 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: Illek, Stefan, Stein, Wilhelm, Walter, Robert, Wirth, Ralph
• Primary Examiner(s): Wilczewski, Mary
• Assistant Examiner(s): DUONG, KHANH B
• Application Number:
  US11/597,928
• Publication Number:
  US 20090008751A1
• Time in Patent Office: 2,738 Days
• Field of Search: None
• US Class Current: 438/46
• 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 electrically conductive III-V semiconductor layer; and

subsequently annealing;

wherein a first ZnO layer is deposited on a first area of the electrically conductive III-V semiconductor layer, and a second ZnO layer is deposited on a second area of the electrically conductive III-V semiconductor layer, with a deposition temperature of the second ZnO layer increased relative to a deposition temperature of the first ZnO layer such that a conductivity of the second area of the electrically conductive III-V semiconductor layer is at least less reduced than a conductivity of the first area of the electrically conductive III-V semiconductor layer during annealing.

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

C.

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

4. The method of claim 1, wherein the ZnO layers are structured before annealing.

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

C. and 500°

C.

6. The method of claim 1, wherein the ZnO layers are doped with Al.

7. The method of claim 1, wherein the electrically conductive 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 of claim 1, wherein the electrically conductive III-V semiconductor layer is p-doped.

9. The method of claim 1, wherein the electrically conductive III-V semiconductor layer is contained in an optoelectronic device.

10. The method according to claim 9, wherein the optoelectronic device contains a radiation emitting active zone and a current flow through subareas of active zone is reduced by the area having the reduced electrical conductivity.

11. The method according to claim 10, wherein the area having the reduced electrical conductivity is positioned between an electrical connecting contact of the optoelectronic device and the radiation emitting active zone.

12. The method of claim 1, wherein the ZnO layer is removed after the annealing.

13. The method according to claim 1, wherein the second ZnO layer is deposited at a temperature greater than 150°

C.

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

C. inclusive and 120°

C. inclusive.

15. The method of claim 1, wherein an electrical conductivity of the first area of the III-V semiconductor layer is reduced by at least a factor of 2, relative to laterally adjacent areas of the III-V semiconductor layer.

16. The optoelectronic semiconductor device according to claim 1, wherein an electrical conductivity of the first area of the III-V semiconductor layer is reduced by at least a factor of 2, relative to laterally adjacent areas of the III-V semiconductor layer.

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

18. The optoelectronic semiconductor according to claim 17, wherein the ZnO layers are doped with Al.

19. The optoelectronic semiconductor according to claim 17, 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.

20. The optoelectronic semiconductor device according to claim 17, 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.

21. The optoelectronic semiconductor device according to claim 20, wherein the first ZnO layer and the second ZnO layer jointly form a current dispersing layer.

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