Double-groove type SiC MOSFET cellular structure, device and manufacturing method

Abstract

The invention discloses a double-groove type SiC MOSFET cellular structure and device and a manufacturing method thereof, the double-groove type SiC MOSFET cellular structure comprises an N + + type SiC substrate, an N-type SiC drift layer, a P type base region and an N + type source region, the N-type SiC drift layer is located above the N + + type SiC substrate and is provided with a source electrode groove and a grid electrode groove, and the bottom of the source electrode groove is provided with an N type hole blocking layer and a source electrode P + type shielding layer; an N-type current conducting layer and a grid P + type shielding layer are arranged at the bottom of the grid groove, and a grid dielectric layer and a grid electrode are arranged in the grid groove; the P-type base region and the N + type source region are located on the N-type SiC drift layer between the source trench and the gate trench and are arranged from bottom to top. Shielding of the drain voltage is further enhanced, the electric field peak value and the gate-drain capacitance of the gate dielectric layer are reduced, the reliability of the gate dielectric layer and the working frequency of the device are improved, the on-resistance of the device can be reduced, and the short-circuit capability of the device can be enhanced.

Description

technical field [0001] The invention relates to the technical field of transistor electronic device preparation, in particular to a double-groove SiC MOSFET cell structure, a device and a manufacturing method thereof. Background technique [0002] Silicon carbide (SiC) is a third-generation semiconductor material. The band gap is three times that of silicon (Si), the first-generation semiconductor material, the critical breakdown electric field strength is ten times that of Si, and the electron saturation drift rate is Si 2 times that of Si, and the thermal conductivity is 3 times that of Si, which makes SiC power semiconductor devices, especially SiC MOSFETs, have significant performance advantages such as high temperature, high voltage, high frequency, and high efficiency, and have broad application prospects in power electronic systems. [0003] A key challenge for SiC MOSFETs is in SiC / SiO 2 There are interface states and the scattering effect of trapped charges on elec...

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Problems solved by technology

[0005] In addition, in power electronic systems, when the device is in the on state, the load is short-circuited or the device is turned on when the load is short-circuited, which will lead to a rapid increase in the conduction current and instantaneous power

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