Pd对Ni基n型SiC器件的欧姆接触特性影响

Influences of Pd film on Ni-based ohmic contacts to n-type SiC

采用电子束蒸发法沉积Ni膜,对Ni膜进行650～1 150℃的热处理,研究了不同Ni层处理温度对欧姆接触的影响,再经过900～1 050℃热处理,欧姆接触比电阻率能够达到10-6,验证了Ni2Si化合物促进了欧姆接触的形成;采用磁控溅射法沉积Pd和Au层,对比了Au/Pd/Ni电极和Au/Ni电极结构的欧姆接触特性,Au/Pd/Ni结构电极的欧姆接触特性比Au/Ni结构电极稳定,接触势垒低.

Ni film is formed using electron beam evaporation method.The sample with Ni film is heated from 650℃ to 1 150℃,different is studied.The result indicate pc the sample heated with 900℃-1050℃ dropped to 10^-6 degree.This confirm Ni2 Si improved the forming of ohmic contracts. Pd film and Au film is formed by magnetron sputtering method. Comparing the Au/Pd/Ni sample with the Au/Ni sample,it is found ohmic contracts of the Au/Pd/Ni sample is more stable than ohmic contracts of the Au/Ni sample and the barrier of the Au/Pd/Ni sample is lower than the barrier of the Au/Ni sample.