Fabrication and Characteristics of Ion-implanted 4H Silicon Carbide Metal-Semiconductor Field-Effect Transistors on a P-Type Epilayer

Abstract

The methods for the design and fabrication of ion-implanted 4H silicon carbide (SiC) metal-semiconductor field-effect transistors (MESFETs) have been studied. The N-well regions are formed by three-fold (Sample A) and four-fold (Sample B) nitrogen ionimplantation on Si-face P-type epilayers with a net accept doping concentration of 6.5×10^15 cm^(-3) grown at american corporation Cree. The layout with testing structures has been designed. The locations of the peak concentration and the longitudinal straggles of the implanted ions are simulated by the Monte Carlo simulator TRIM. The box-like profile for the implantation layer is calculated by the Gauss expression. According to the structure of the device and the energy band for the implantation layer, the theoretical equation of the channel depth for the ion-implantation technique is given and calculated. The processes used to determine the implantation energies and doses are discussed. The experiment for ion-implanted 4H-SiC MESFETs is performed. The Ohmic and Schottky contact metals are annealed Ni/Cr alloy and Ti/Pt double-metal layers, respectively, and the pad metallization is Au. The performance of the current-voltage characteristics of the two samples of ion-implanted 4H-SiC MESFETs has been given at the end.