Charge storage type insulated gate bipolar transistor and preparation method thereof

Abstract

The invention discloses a charge storage type insulated gate bipolar transistor and a preparation method thereof, and belongs to the technical field of power semiconductors. On the basis of a traditional charge storage type IGBT device structure, a charge storage layer and a drift region form a heterojunction structure, so that the energy band on one side, close to an emitting electrode, of the drift region is bent, so as to form a barrier for blocking a few carriers in the drift region from flowing away from a base region, and the concentration of a few carriers in the current position is increased. According to the invention, the carrier distribution concentration of the drift region is improved, and the conductance modulation effect of the IGBT is enhanced, so that the positive conducting voltage drop Vceon of the device is reduced, and the compromise between the positive conducting voltage drop Vceon of the IGBT and the turn-off loss Eoff is optimized; and the defect that the breakdown voltage is reduced when the Vceon of the traditional charge storage layer is reduced is overcome; and a combination of different forbidden band width semiconductor materials for forming the heterojunction structure can be adjusted, so that the working characteristics of the device can be further optimized.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and in particular relates to a charge storage type insulated gate bipolar transistor and a preparation method thereof. Background technique [0002] IGBT is a device composed of MOSFET (input stage) and PNP transistor (output stage). It has the characteristics of easy driving, low input impedance and fast switching speed of MOSFET devices, and the on-state current density of bipolar devices. Large, low conduction voltage, low loss, and good stability. Based on these excellent device characteristics, IGBT has become a mainstream power device widely used in medium and high voltage fields in recent years, such as high-speed rail, electric vehicles, motor drives, grid-connected technology, energy storage power stations, AC / DA conversion and frequency conversion speed regulation and other fields . The use of IGBT for power conversion can improve the efficiency and quality of powe...

AI Technical Summary

Problems solved by technology

[0008] The present invention aims at the adverse effects of the doping concentration and thickness of the charge storage layer on the breakdown voltage of the device in the prior art, and limits the compromise between the breakdown voltage of the device, the forward conduction voltage drop and the turn-off loss, and provides A charge storage type insulated gate bipolar transistor with a heterojunction structure, which makes the charge storage layer and the drift region form a heterojunction in traditional devices, causing the energy band of the drift region to bend, so that the minority carriers in the drift region Form a potential barrier to increase the minority carrier concentration near the emitter in the drift region, improve the carrier concentration distribution in the drift region, and obtain lower forward voltage drop and better forward voltage The trade-off relationship between drop and turn-off loss avoids the adverse effect of increasing the concentration of the charge storage layer on the breakdown voltage of the device