Simulation of the Effects of Postimplantation Annealing on Silicon Carbide DMOSFET Characteristics

Technological control of doped regions is exceptionally important for all semiconductor devices. For the wide bandgap semiconductor silicon carbide, the activation state of dopants is determined by the postimplantation annealing step which consequently affects device operation and characteristics. We perform a detailed analysis of the effects of postimplantation annealing on the electrical characteristics of silicon carbide-based double-implanted metal-oxide-semiconductor field-effect transistors. We predict acceptor and donor concentrations according to various annealing times, temperatures, and total doping concentrations. The findings are used as a basis for the combined process and device simulations, providing the capability to characterize a reference device and predict the annealing dependence of output and transfer characteristics. Our results are in excellent agreement with the experiments and show precisely how annealing steps influence channel potential, drain current, ON-state resistance, and threshold voltage. Finally, we predict device characteristics based on the annealing variables, showing a high sensitivity of the threshold voltage on annealing time and temperature.