III-nitride superlattice structures

• US 5,831,277 A
• Filed: 03/19/1997
• Issued: 11/03/1998
• Est. Priority Date: 03/19/1997
• Status: Expired due to Fees

• Current Assignee: MP Technologies, LLC (APi Group Corp.)
• Original Assignee: Northwestern University
• Inventors: Razeghi, Manijeh
• Primary Examiner(s): Tran, Minh Loan
• Application Number:
  US08/820,586
• Time in Patent Office: 594 Days
• Field of Search: 257/15, 257/17, 257/18, 257/22, 257/96, 257/97, 257/102, 257/103
• US Class Current: 257/15
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 21/02378 Silicon carbide
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02507 Alternating layers, e.g. superlattice
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/02579 P-type
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 29/155 Comprising only semiconductor materials H01L29/154 takes precedence
• CPC Class Codes: H01L 31/035236 Superlattices; Multiple quantum well structures
• CPC Class Codes: H01L 31/1035 the devices comprising active layers formed only by AIIIBV compounds
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

The subject invention involves the p-type doping of Al_x Ga_1-x N thin films with a III-nitride composition and specifically a {Al_x Ga_1-x N/GaN} short-period superlattice structure of less than 5000 Å thickness in total in which both the barriers and the wells are p-type doped with Mg.

Claims

1. A photoemitter device, comprising a substrate, an upper and lower contact layer, an upper and lower confinement layer, an undoped active layer between said upper and lower confinement layer and a cap layer;

said upper confinement layer comprising a superlattice structure having from about 5 to about 500 alternating layers of Al_x Ga_1-x N and GaN (0≦

X≦

1) with a total thickness of less than 5000 Å

, and said lower confinement layer consisting essentially of one GaN layer and one Ga_x Al_1-x N layer.

2. The device of claim 1 wherein said substrate is Al₂ O₃ or SiC.

3. The device of claim 1 wherein said lower contact layer is GaN:

Si.

4. The device of claim 1 wherein said lower contact layer is doped with a dopant selected from the group consisting of Si, Ge and Sn.

5. The device of claim 1 wherein said active layer is GaN or InGaN.

6. The device of claim 1 wherein the layers of GaN of said upper confinement layer each have a thickness of between about 10 to about 30 Å

and p-type doping of≧

2×

10¹⁷ cm^-3.

7. The device of claim 1 wherein the layers of Al_x Ga_1-x N of said upper confinement layers have a thickness of about 10 to about 100 Å

and p-type doping of≧

2×

10¹⁷ cm^-3.

8. The device of claim 1 wherein the layers of Al_x Ga_1-x N of said upper confinement layers have a thickness of about 10 to about 100 Å

.

9. The device of claim 1 wherein said upper confinement layers are doped with a p-type dopant.

10. The device of claim 1 wherein said upper confinement layers are doped with Mg, Be, Zn or Cd.

11. A photoemitter device, comprising a substrate, an upper and lower contact layer, an upper and lower confinement layer, an undoped active layer between said upper and lower confinement layer and a cap layer;

said upper confinement layer comprising a superlattice structure having from about 5 to about 500 alternating layers of Al_x Ga_1-x N and GaN (0≦

X≦

1) with a total thickness of less than 5000 Å

, and said layers of GaN in said superlattice structure each being of substantially equal thickness.

12. The device of claim 11 wherein said substrate is Al₂ O₃ or SiC.

13. The device of claim 11 wherein said lower contact layer is GaN:

Si.

14. The device of claim 11 wherein said lower contact layer is doped with a dopant selected from the group consisting of Si, Ge and Sn.

15. The device of claim 11 wherein said active layer is GaN or InGaN.

16. The device of claim 11 wherein the layers of GaN of said upper confinement layers have a thickness of between about 10 to about 30 Å

and p-type doping of≧

2×

10¹⁷ cm^-3.

17. The device of claim 11 wherein the layers of Al_x Ga_1-x N of said upper confinement layer have a thickness of about 10 to about 100 Å

and p-type doping of≧

2×

10¹⁷ cm^-3.

18. The device of claim 11 wherein the layers of Al_x Ga_1-x N of said upper confinement layer have a thickness of about 10 to about 100 Å

.

19. The device of claim 11 wherein said upper confinement layer is doped with a p-type dopant.

20. The device of claim 11 wherein said upper confinement layer is doped with Mg, Be, Zn or Cd.