Formation of low resistivity ohmic contacts to n-type 3C-SiC

Abstract

In this study, the dependence of nickel contacts to n-type 3C-SiC on anneal temperature is characterized by the linear transmission line method. It is found that Ni contacts begin to exhibit ohmic behavior after annealing at 700 °C, and the specific contact resistivity decreases gradually with increasing anneal temperature. A low contact resistivity of 1.4×10 −5 Ω cm 2 was obtained after annealing at 1000 °C. Phosphorus was implanted into 3C-SiC epilayer and then activated at 1050, 1150, 1250 and 1350 °C, respectively. Both the sheet resistance of the 3C-SiC epilayer and the specific contact resistivity of Ni contacts decrease monotonically with increasing activation temperature. Results from Ni/Si bilayer contacts with varying layer thickness ratios (50 nm/180 nm, 50 nm/90 nm and 50 nm/50 nm) are also reported. Ni/Si bilayer contacts are found to be inferior to pure Ni contacts.