Abstract
Two new types of thyristors, a static induction and a beam base type, are fablicated and measured, which have structures based on SIT. They have switching characteristics as fast as 1.1 µs for turn-on and 0.35 µs for turn-off, and a new ability to cut off dc by the change of the gate bias or the external resistance. The forward blocking voltage more than 200 V and the current density more than 100 A/cm2 have been achieved. The turn-off time decreases as increasing the gate bias voltage, and as decreasing the cathode current, gate external resistance and the channel width. A part of carriers injected from the anode flow out to the gate, which contribute to the switching. They are expected to be used in high-power and high-speed switching field.