基于Ni/Ag/Pt的P型GaN欧姆接触

Ni/Ag/Pt Ohmic Contacts to P-type GaN

提出了新型的Ni/Ag/Pt结构作为具有高光学反射率、低比接触电阻率(SCR)的p-GaN欧姆接触电极。在Ni/Ag/Pt厚度分别为3 nm/120 nm/2 nm的条件下,在500℃、O2气氛中退火3 min,获得了80%的光学反射率(460 nm处)和4.43×10-4Ω.cm2的SCR,样品的表面均方根(RMS)粗糙度约为8nm。俄歇电子能谱(AES)分析表明,Pt很好地改善了Ag基电极退火后的表面形貌,Ni、Ag对形成良好的欧姆接触起了重要的作用。

A novel Ni/Ag/Pt（3 nm/120 nm/2 nm）structure used as ohmic contact to p-GaN with high reflectance and low specific contact resistivity（SCR） was presented. After annealed at 500℃ in O2 ambient for 3 min,the SCR with 4.43× 10^-4 Ω· cm^2 and optical reflectance of 80 % at 460 nm were obtained. The root-mean-square（RMS） roughness of the Ni/Ag/Pt sample surface is 10 nm. Auger electronic spectroscope（AES） analysis shows that Ni and Ag are important for ohmic contact, and the surface morphology of Ag-based ohmic contacts is improved by Pt.