A shielded gate mosfet device and method of manufacture

Abstract

The application relates to the technical field of semiconductors, and discloses a shielded gate MOSFET device and a preparation method. The preparation method comprises the following steps: providing an epitaxial layer, wherein the epitaxial layer comprises a first surface and a second surface arranged oppositely; forming a groove on the first surface, and forming a shielded gate structure in the groove; sequentially injecting into the epitaxial layer from the first surface to form a first doped region and a second doped region; forming an interlayer dielectric layer on the first surface, etching the interlayer dielectric layer to form a contact hole, and making the contact hole pass through the second doped region and extend into the first doped region; injecting doped ions into the bottom of the contact hole towards the epitaxial layer to form a third doped region; wherein the depth of the third doped region is greater than the depth of the first doped region, and the depth of the third doped region is less than the depth of the groove. The technical scheme aims to improve the dynamic loss under high-frequency working conditions and reduce the on-resistance of the device.

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