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.

Key words: static induction transistor,  parasitic effect,  breakdown voltage,  deep trench