A novel Ni/Ag/Pt Ohmic contact to P-type GaN for flip-chip light-emitting diodes

作者：Ma Hong-Xia^*; Han Yan-Jun; Shentu Wei-Jin; Zhang Xian-Peng; Luo Yi

来源：Chinese Physics Letters, 2006, 23(8): 2299-2302.

• LOW-RESISTANCE
• OXIDIZED NI/AU
• MECHANISM
• FILMS

We present a high-quality Ni/Ag/Pt Ohmic contact to p-type GaN. After the sample is annealed at 500 degrees C in O-2 ambient for 3 min, a specific contact resistance as low as 2.6 x 10(-5) Omega.cm(3) and an optical reflectivity of 82% at 460 nm are obtained. The Auger electron spectroscopy analysis shows that the Pt layer can improve the surface morphology and thermal reliability of the annealed Ag-based electrode, Ag plays a key role in achieving good ohmic contact due to the outdiffusion of Ga into Ag forming Ga vacancies which increase the hole concentration, while the surface contamination of p-type GaN is reduced by Ni.

• 出版日期2006-8
• 单位清华大学深圳研究生院; 集成光电子学国家重点实验室; 清华大学