Proton irradiated high speed SI-thyristors

A static induction thyristor (SIThy) is a semiconductor power device with many advantages. The authors report on the normally-off type SIThy with a surface-gate structure. The main current of a SIThy is controlled by a gate potential. At the turn-off process of a SIThy, the carrier injection from the anode region to the high resistivity region results to the tail current as well as GTO thyristor. Methods to reduce the tail current and to increase the switching speed are reported. One of them is the decrease of carrier lifetime with heavy metal diffusion or the use of anode shorting structure. A novel lifetime control method is proton irradiation in which a dual-sided proton irradiation technique is carried out to decrease the carrier lifetime locally and to increase the electrical performance of the SIThy