Electrical measurements of n-type 4H- silicon carbide metal contacts

Silicon Carbide (SiC) is an attractive wide bandgap semiconductor for high temperature, high power or high frequency applications. In this work , we study metal contacts on single crystal silicon carbide(Polytype 4H SiC). The polytype 4H SiC exhibits high electron mobility and low mobility anisotropy compared to other SiC polytypes. Contacts are prepared by evaporating metals of different work functions on n type 4H SiC. The electrical characteristics of the junctions obtained are determined as a function of temperature. Analysis of the current-voltage characteristics gives information on the nature of the contact (Ohmic type or Schottky barrier rectifying type), capacitance-voltage measurements gives information about the barrier height, doping concentration as well as the distribution of shallow and deep levels near the surface of the contact.