Double-trapezoid-groove protection trapezoid-groove silicon carbide MOSFET device and manufacturing method thereof

Abstract

The invention relates to a double-trapezoid-groove protection trapezoid-groove silicon carbide MOSFET device and a manufacturing method. The MOSFET device comprises a drain electrode substrate located at the bottom, a drain electrode epitaxial layer located in the middle, a source electrode metal layer located at the top, a grid electrode strip embedded in the drain electrode epitaxial layer and a drain electrode metal layer located at the bottom of the drain electrode substrate. The gate strip is arranged in the first groove with the inverted trapezoidal section in the drain epitaxial layer and is insulated through the interlayer film strip and the gate dielectric layer; a redefined channel layer is formed along the contour surface of the first groove so as to conduct the source metal layer and the drain metal layer; and a buffer layer is formed along the contour surface of the second groove with the inverted trapezoidal section in the drain electrode epitaxial layer, so that PN junction isolation is formed between the source electrode metal layer and the drain electrode extension layer. According to the invention, the electron flow of the drain substrate and the top surface source electrode can uniformly reach each region of the drain electrode metal layer.

Description

technical field [0001] The present application relates to the field of semiconductor transistors, in particular to a silicon carbide MOSFET device with double trapezoidal grooves protecting trapezoidal grooves and a manufacturing method. Background technique [0002] Silicon carbide belongs to the third-generation semiconductor material because of its wide bandgap (bandgap greater than 2.2eV), high thermal conductivity, high breakdown field strength, high electron saturation rate and high radiation resistance , can achieve better electron concentration and motion control, and is more suitable for making electronic devices used in high temperature, high pressure, high frequency, strong radiation and high power. [0003] At present, MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, Metal-Semiconductor Field-Effect Transistor) devices have a variety of structures, mainly including the following types: planar MOS tube, trench MOS tube and super junction MOS tube . Amo...

AI Technical Summary

Problems solved by technology

Among them, the planar MOS transistor structure is to design the source contact and the drain contact on the same surface of the semiconductor substrate. With the development of the trend of wafer thinning and device miniaturization, the problem of leakage current from the back of the wafer will become more and more serious. It is a difficult problem that needs to be faced and overcome; trench MOS transistors are limited by the silicon limit, which leads to the inability to increase the power density of devices with the same on-resistance occupying a larger wafer area; and the process technology of super junction MOS transistors is too complex

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