Low-power-consumption and high-reliability trench silicon carbide MOSFET device

Abstract

The invention provides a low-power-consumption and high-reliability trench silicon carbide MOSFET device which comprises an N-type substrate, an N-type epitaxial layer, a first P-Body region, first P+ contact region, a first N + contact region, a second P- body region, a second P + contact region, a second N + contact region, an oxide layer, a groove grid, a metal electrode and drain electrode. According to the SiC MOSFET device, the on-resistance can be significantly reduced through the parallel connection of four channels, and the reliability of the oxide layer of the device can be enhancedand partial gate leakage capacitance can be shielded through wrapping and protection of the second P- body to the groove grid so that the switching loss of the device can be reduced. When the deviceis short-circuited, the JFET region formed by the first P- body region and the Second P- body region is cut off so as to reduce the saturation current of the device and improve its short-circuit capability.

Description

Technical field [0001] The invention belongs to the technical field of power semiconductor devices, and in particular is a trench silicon carbide MOSFET device with low power consumption and high reliability. Background technique [0002] As one of the representatives of the third-generation wide-bandgap semiconductor materials, silicon carbide (Silicon Carbide) material has a large forbidden band width (3.26eV) and a high critical electric field (3×10 6 V / cm), high carrier saturation drift velocity (2×10 7 cm / s), high thermal conductivity (490W / Mk), and good thermal stability. It is an excellent material for the preparation of high-voltage power electronic devices. It has a broad field of high-power, high-temperature, high-pressure and radiation-resistant power electronics. Application prospects. [0003] MOSFET is the most widely used gate control device structure in silicon carbide power devices. Since the silicon carbide MOSFET is a device characterized by a unipolar transport...

AI Technical Summary

Problems solved by technology

Although the P+ shielding layer at the bottom of the trench gate can strongly protect the oxide layer at the bottom and corners of the trench gate, the oxide layer on the sidewall of the trench will still be challenged by a high electric field in the blocking state, so the P+ shielding layer The introduction cannot completely solve the reliability problem that the trench gate oxide layer is impacted by high electric field

[0005] Due to the poor interface state between the current silicon carbide material and the gate oxide dielectric, the channel mobility is too low, and the conduction characteristics of the trench gate silicon carbide MOSFET are still far from the theoretical limit.

Due to the large gate-to-drain capacitance of the trench-gate SiC MOSFET, its switching loss is high

At the same time, due to its high current saturation current, its short-circuit capability is weak

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