Improvements on high voltage performance of power static induction transistors

Abstract

A novel structure for designing and fabricating a power static induction transistor (SIT) with excellent high breakdown voltage performance is presented. The active region of the device is designed to be surrounded by a deep trench to cut off the various probable parasitical effects that may degrade the device performance, and to avoid the parallel-current effect in particular. Three ring-shape junctions (RSJ) are arranged around the gate junction to reduce the electric field intensity. It is important to achieve maximum gate-source breakdown voltage BVGS, gate-drain breakdown voltage BVGD and blocking voltage for high power application. A number of technological methods to increase BVGD and BVGS are presented. The BVGS of the power SIT has been increased to 110 V from a previous value of 50–60 V, and the performance of the power SIT has been greatly improved. The optimal distance between two adjacent ring-shape junctions and the trench depth for the maximum BVGS of the structure are also presented.