1200 V MCCT: a new concept three terminal MOS-gated thyristor

Abstract

High power semiconductor devices are required for various applications like a motor control in traction system. Desired device characteristics for such applications are low forward voltage drop, high current capability and large blocking voltage capability. Insulated Gate Bipolar Transistor (IGBT) is now widely accepted for many applications due to its simple gate control and current saturation feature, and many studies have been done for its high voltage application. It has been found that this device structure has a high forward voltage drop at a large current density when designed for the high voltage application. As an alternative, MOS-gated thyristor structures such as MOS Controlled Thyristor (MCT) and Base Resistance controlled Thyristor(BRT) have been studied for the high voltage application because of its simple gate drive capability and low forward voltage drop. However, since this device does not have the current saturation feature, passive protection must be provided for its stable operation. In this paper, a new class of MOS-gated thyristor structure named MOS Controlled Cascode Thyristor (MCCT) which exhibits a superior short circuit withstand capability as well as the low forward voltage drop will be demonstrated for the first time. Furthermore, this device shows a fast switching speed which is comparable to that of an IGBT and an excellent maximum turn-off capability, simultaneously.