Method for making III-Nitride laser and detection device

• US 5,834,331 A
• Filed: 10/17/1996
• Issued: 11/10/1998
• Est. Priority Date: 10/17/1996
• Status: Expired due to Fees

• Current Assignee: Manijeh Razeghi
• Original Assignee: Northwestern University
• Inventors: Razeghi, Manijeh
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): Pham, Long
• Application Number:
  US08/733,271
• Time in Patent Office: 754 Days
• Field of Search: 438/36, 438/39, 438/40, 438/45, 438/46, 438/504, 438/506, 438/507, 438/508, 438/509, 438/289, 438/334, 257/744, 257/745, 257/12, 257/13, 148/DIG. 3, 148/DIG. 65, 148/DIG. 66, 372/43, 372/45
• US Class Current: 438/40
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 31/1844 comprising ternary or quaternary compounds, e.g. Ga Al As, In Ga As P
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 5/0213 Sapphire, quartz or diamond based substrates
• CPC Class Codes: H01S 5/343 in AIIIBV compounds, e.g. AlGaAs-laser , InP-based laser
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials
• CPC Class Codes: Y10S 148/003 Anneal
• CPC Class Codes: Y10S 148/065 Gp III-V generic compounds-processing
• CPC Class Codes: Y10S 148/066 Gp III-V liquid phase epitaxy

Abstract

A p-i-n structure for use in photoconductors and diodes is disclosed, being formed of an Al_x Ga_1-x N alloy (X=0→1) with In_y Ga_1-Y N (Y=0→1) which as grown by MOCVD procedure with the p-type layer adjacent the substrate. In the method of the subject invention, buffer layers of p-type material are grown on a substrate and then doped. The active, confinement and cap layers of n-type material are next grown and doped. The structure is masked and etched as required to expose a surface which is ion implanted and annealed. A p-type surface contact is formed on this ion-implanted surface which is of sufficiently low resistance as to provide good quality performance for use in a device.

Claims

1. A method of growing a III-V nitride compound semiconductor, comprising the steps of:

a) providing a substrate;

b) growing a buffer layer on said substrate;

c) growing, doping and annealing a p-type lower contact layer on said buffer layer;

d) growing, doping and annealing a p-type lower confinement layer over said lower contact layer;

e) growing an active layer over said lower confinement layer;

f) growing and doping an n-type upper confinement layer over said active layer;

g) growing an upper n-type contact layer over said upper confinement layer;

h) doping said upper contact layer and thereby forming an unfinished structure;

i) masking and etching said unfinished structure to expose said lower contact layer;

j) ion implanting said exposed lower contact area with ions selected from the Group consisting of Ag, Hg, Cu, Si and Ge; and

k) making an ohmic contact on each of said n-type and p-type contact layers to form said III-V nitride compound semiconductor.

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

3. The method of claim 1 wherein said lower contact layer is GaN or AlGaN and is doped with Mg.

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

5. The method of claim 1 wherein said active layer is In_y Ga_1-y N, (0≦

Y≦

1) , Al_x Ga_1-x N (0≦

X≦

1) or the superlattice structure of GaN/Ga_1-z In₂ N (0≦

Z≦

1).

6. The method of claim 1 wherein said upper confinement layer is Ga_x Al_1-x N (0≦

X≦

1).

7. The method of claim 1 wherein said upper contact layer is GaN.

8. The method of claim 1 wherein said upper contact layer is doped with Si or Ge.

9. A method of preparing a III-Nitride based laser diode structure comprising the steps of:

a) providing a p-i-n structure by growing and doping a lower p-type contact layer by growing a p-type layer on a substrate;

b) annealing said p-type layer;

c) growing, doping a p-type confinement layer over said p-type layer;

d) annealing said p-type confinement layer;

e) growing an active layer on said confinement layer;

f) growing and doping a n-type confinement layer over said active layer;

g) growing and doping an upper n-type contact layer over said n-type confinement layer;

h) masking and etching said p-i-n structure to expose said lower contact layer;

i) ion implanting said exposed contact layer with Ag, Hg or Cu; and

j) forming an ohmic contact on said ion implanted lower contact layer and on said upper contact layer thereby forming said III-Nitride based laser diode structure.

10. The method of claim 9 wherein said structure is grown on a substrate which is selected from the group consisting of Al₂ O₃, SiC, GaAs, Si, MgO, ZnO, LiGaO₃, LiAlO₂, MgAlO₄ and GaN.

11. The method of claim 10 further including the step of forming a buffer layer on said substrate.

12. The method of claim 9 wherein said lower contact layer is GaN and AlGaN.

13. The method of claim 9 wherein said lower contact layer is doped with a dopant selected from the group consisting of Mg, Zn, Be, Si, Ge and Sn.

14. The method of claim 9 wherein said active layer is In_y Ga_1-y N, (0≦

Y≦

1), Al_x Ga_1-x N (0≦

X≦

1) or the superlattice structure of GaN/Ga_1-z In_z N (0≦

Z≦

1).

15. The method of claim 9 wherein said upper contact layer is AlGaN or GaN.

16. The method of claim 9 wherein said upper contact layer is doped with a dopant selected from the group consisting of Mg, Zn, Be, Si, Ge and Sn.