Abstract: In a gate insulated static induction thyristor with a split gate type shorted cathode structure, a first gate of the split gate structure is used as a cathode short-circuit gate and the cathode region is formed in the second gate. A MOS structure is formed on the second gate as a control gate electrode isolated therefrom. Since the channel integration density is high, the area efficiency increases. The MOS gate structure suppresses the minority carrier (hole) storage effect to permit high-speed swtching of the thyristor, and the shorted cathode structure provides for increased maximum controllable current/voltage durability. The split gate structure can be used in combination with planar, buried, recessed and double gate structures.

Abstract: In a gate insulated static induction thyristor with a split gate type shorted cathode structure, a first gate region of the split gate structure is used as a cathode short-circuit gate and the cathode region is formed between the first and second gate regions. A MOS structure is formed on the second gate region as a insulated gate control gate region electrode isolated therefrom. The MOS gate structure suppresses the minority carrier (hole) storage effect to permit high-speed switching of the thyristor, and the shorted cathode structure provides for increased maximum controllable current/voltage durability. The split gate structure can be used in combination with planar, buried, recessed and double gate structures.

Abstract: A static induction thyristor having a mesh like gate region in front of the cathode, and between the gate region and the cathode a high resistance region having effective impurity concentration of 10.sub.11 cm.sup.-3 -5.times.10.sup.14 cm.sup.-3 is interposed, and the voltage gain decided by the gate length, gate interval and the gate-to-anode distance is made 10 or more so that the forward voltage drop is small, providing high speed switching ability and a large reverse breakdown voltage.