Method for manufacturing gallium nitride based transparent conductive oxidized film ohmic electrodes

• US 7,022,597 B2
• Filed: 07/16/2004
• Issued: 04/04/2006
• Est. Priority Date: 07/16/2004
• Status: Active Grant

• Current Assignee: Tekcore Co Limited (Tekcore)
• Original Assignee: Tekcore Co Limited (Tekcore)
• Inventors: Wang, Sung-Li, Peng, Lung-Han, Lin, Chin-Yi, Chang, Chia-Wei, Wu, Han-Ming
• Primary Examiner(s): Nhu, David
• Application Number:
  US10/892,180
• Publication Number:
  US 20060014368A1
• Time in Patent Office: 627 Days
• Field of Search: 438/604, 438/602, 438/603, 438/20, 438/30, 438/46, 438/47, 438/77, 438/92, 438/93, 438/94, 438/172, 438/235, 438/191, 438/194, 438/311, 438/312, 438/309, 438/369, 438/378, 438/491, 438/487, 438/488, 438/796
• US Class Current: 438/604
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

A method for manufacturing gallium nitride based transparent conductive oxidized film ohmic electrodes includes forming a transparent conductive film on a GaN layer, forming a transparent conductive hetero-junction of opposing electrical characteristics on a transparent conductive film on the surface of the GaN layer through an ion diffusion process, and laying a metallic thick film on the surface of the transparent conductive hetero-junction for wiring process in the later fabrication operation. Thus through the electron and hole tunneling effect in the ion diffusion process the Fermi level of the hetero-junction may be improved to form an ohmic contact electrode.

Claims

1. A method for manufacturing gallium nitride (GaN) based transparent conductive oxidized film ohmic electrodes forming a transparent conductive film on a GaN layer, comprising steps of:

(a) forming a GaN layer on the substrate;

(b) forming the transparent conductive film of a high work function on a surface of the GaN layer;

(c) forming a transparent conductive hetero-junction of opposite electric characteristics through an ion diffusion process on the transparent conductive film on the surface of the GaN layer; and

(d) laying a metallic thick film on the transparent conductive hetero-junction for wiring process in later fabrication operations;

wherein the ion diffusion process generates electron and hole tunneling effect to transform the transparent conductive hetero-junction to an ohmic contact electrode.

2. The method of claim 1, wherein the transparent conductive film of a high work function is formed by an oxide film selected from a group consisting of Ga₂O₃, In₂O₃, and Al₂O₃.

3. The method of claim 1, wherein the transparent conductive film (20) of a high work function is formed by combining Ga₂O₃, In₂O₃, and Al₂O₃.

4. The method of claim 1, wherein the ion diffusion process is accomplished by ion plantation or high temperature impurity diffusion.

5. The method of claim 1, wherein ions used in the ion diffusion process is a p-type mixture consisting of zinc (Zn), nickel (Ni), cobalt (Co), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and silver (Ag).

6. The method of claim 1, wherein the metallic thick film is selectively formed of a monoxide film consisting of titanium (Ti), aluminum (Al), nickel (Ni) or gold (Au).

7. The method of claim 1, wherein the metallic thick film (30) is a combination of titanium (Ti), aluminum (Al), nickel (Ni) and gold (Au).