Silicon carbide trench gate MOSFET and manufacturing method thereof

Abstract

The invention provides a silicon carbide trench gate MOSFET and a manufacturing method thereof. The silicon carbide trench gate MOSFET comprises a substrate with a first doping type, an epitaxial layer which is formed on the substrate and has the first doping type, an epitaxial well region which is formed above the epitaxial layer and has a second doping type, a first source contact region which is formed in the epitaxial well region and has a first doping type, a second source contact region which has a second doping type, atrench gate, a source electrode and a drain electrode, wherein thetrench gate comprises a gate dielectric and a gate electrode. The silicon carbide trench gate MOSFET is characterized by comprising a concave injection type current diffusion region which wraps the bottom of a trench gate and has a first doping type, and the bottom of the injection type current diffusion region is not higher than the bottom of an epitaxial well region. The injection type current diffusion region is reasonably arranged, the saturation current of the device can be limited, meanwhile, the electric field peak value and the current position can be separated, the heating power is reduced, and the short-circuit capacity of the device is improved.

Description

technical field [0001] The invention relates to a semiconductor device, in particular to a silicon carbide trench gate MOSFET and a manufacturing method thereof. Background technique [0002] The performance of traditional silicon-based semiconductor devices has gradually approached the physical limit of materials, and the third-generation power semiconductor devices using SiC materials are used in high-power density and high-efficiency devices due to their excellent high frequency, high voltage, and strong thermal conductivity. Has a strong appeal. SiC MOSFET devices are gradually used in application scenarios such as electric vehicles and photovoltaic inverters due to their easy driving and high switching frequency. SiC MOSFET devices are mainly right-plane gate double-diffused SiC MOSFETs and trench gate MOSFETs. Compared with the planar gate MOSFET, the trench gate MOSFET eliminates the resistance of the JFET region, and at the same time has a higher channel density, w...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the above problems in the existing situation, the present invention proposes a silicon carbide trench gate MOSFET and its manufacturing method

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