4H-silicon carbide based N-channel accumulating high-voltage insulated gate bipolar transistor

Abstract

The invention discloses a 4H-silicon carbide based N-channel accumulating high-voltage insulated gate bipolar transistor. The 4H-silicon carbide based N-channel accumulating high-voltage insulated gate bipolar transistor is characterized in that the traditional inversion channel is replaced by an accumulation channel and an N type base region is adopted between a P type shielding layer and a gate oxide layer. The thickness and the dosage concentration of the N type base region are selected to guarantee that the region is completely deleted when the gate voltage is zero, and therefore, the bipolar transistor is closed in a normal state. When the gate voltage is high enough, the accumulation channel is formed at the interface of SiO2 / SiC so that the bipolar transistor can be switched on. Current carriers in an accumulation layer are distributed farther away from the surface than current carriers in an inversion layer and a higher effective migration rate of the accumulation channel can be expected, and therefore, the differential on resistance of the 4H-SiC based high-voltage N-channel IGBT and the on voltage drop under specific on current density and gate voltage can be effectively reduced by replacing the traditional inversion channel with the accumulation channel, and consequently, the energy loss of the bipolar transistor in the on state can be effectively reduced.

Description

technical field [0001] The invention relates to a 4H-silicon carbide-based N-channel accumulation type high-voltage insulated gate bipolar transistor, which belongs to the field of high-power semiconductor devices. Background technique [0002] Silicon carbide (SiC) is a wide bandgap semiconductor material. Its superior characteristics, including wide band gap, high thermal conductivity, high critical electric field, etc., make it very suitable for the manufacture of high-power, high temperature and high radiation resistant electronic devices . The material has various polytypes, among which the more common ones include 4H-SiC, 6H-SiC and 3C-SiC. Among the three polytypes, 4H-SiC has a higher critical electric field and mobility of electrons and holes, and a wider band gap. The semiconductor device involved in the present invention uses 4H-SiC material. [0003] Insulated gate bipolar transistor (IGBT) is a semiconductor device that combines the advantages of BJT and MOSFE...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved in the prior art is: 4H-SiC / SiO 2 The effective mobility of the inversion channel at the interface is low

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