A Novel Ni/Ag/Pt Ohmic Contact to P-Type GaN for Flip-Chip Light-Emitting Diodes
MA Hong-Xia1, HAN Yan-Jun2, SHENTU Wei-Jin2, ZHANG Xian-Peng2, LUO Yi1,2
1Graduate School at Shenzhen, Tsinghua University, Shenzhen 518057
2State Key Laboratory on Integrated Optoelectronics, Department of Electronics Engineering, Tsinghua University, Beijing 100084
A Novel Ni/Ag/Pt Ohmic Contact to P-Type GaN for Flip-Chip Light-Emitting Diodes
MA Hong-Xia1;HAN Yan-Jun2;SHENTU Wei-Jin2;ZHANG Xian-Peng2;LUO Yi1,2
1Graduate School at Shenzhen, Tsinghua University, Shenzhen 518057
2State Key Laboratory on Integrated Optoelectronics, Department of Electronics Engineering, Tsinghua University, Beijing 100084
Abstract： We present a high-quality Ni/Ag/Pt Ohmic contact to p-type GaN. After the sample is annealed at 500°C in O2 ambient for 3min, a specific contact resistance as low as 2.6×10-5Ω.cm2 and an optical reflectivity of 82% at 460nm 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.
MA Hong-Xia;HAN Yan-Jun;SHENTU Wei-Jin;ZHANG Xian-Peng;LUO Yi;. A Novel Ni/Ag/Pt Ohmic Contact to P-Type GaN for Flip-Chip Light-Emitting Diodes[J]. 中国物理快报, 2006, 23(8): 2299-2202.
MA Hong-Xia, HAN Yan-Jun, SHENTU Wei-Jin, ZHANG Xian-Peng, LUO Yi,. A Novel Ni/Ag/Pt Ohmic Contact to P-Type GaN for Flip-Chip Light-Emitting Diodes. Chin. Phys. Lett., 2006, 23(8): 2299-2202.
2006, Vol. 23 
