Controlling the characteristics of the MPS rectifier by variation of area of Schottky region

A method of controlling the characteristics of the merged p-i-n Schottky (MPS) rectifier is demonstrated both theoretically and experimentally. It is based on varying the relative area of the p⁺ -n junction and Schottky regions in the device. A curve for the tradeoff between the forward voltage drop and the switching characteristics can be obtained using this method, while maintaining a constant minority-carrier lifetime. It is shown that this curve is superior to that obtained for the p-i-n rectifier using lifetime control techniques. This method of performing the tradeoff has the advantage that it can be done at the design stage, avoiding the problems and additional processing associated with lifetime control. It is also demonstrated that the superior characteristics of the MPS rectifier is retained even when a thick high-resistivity epilayer is used for high blocking voltages up to 900 V