A lateral power semiconductor device

Abstract

The application provides a lateral power semiconductor device, which introduces a first gate dielectric layer, a second gate dielectric layer and a third gate dielectric layer arranged in sequence along a second direction at a gate oxide layer of a conventional lateral power semiconductor device, the thickness of the three layers can be adjusted, and the length along the second direction can be adjusted; the lateral power semiconductor device integrates a first field effect structure and a second field effect structure, wherein the second field effect structure has a lower threshold voltage and adopts a short connection form of a gate and a source. When a parasitic PN junction diode in the device is in a forward bias, current is mainly conducted by the second field effect structure, so that the conduction loss of the whole device is reduced, and the reverse recovery characteristic is improved. When the device is applied to some specific circuits, such as a synchronous Buck converter, the freewheeling loss can be effectively reduced, the reverse recovery characteristic is improved, and the conversion efficiency is improved.

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