Bottom trench Schottky contact sic MOSFET device

Abstract

The invention provides a SiC MOSFET device with Schottky contact at the bottom of the trench, comprising: N-type substrate, N-type epitaxial layer, P-body region, P+ contact region, N+ contact region, oxide layer, gate, and Schottky contact electrode, P-shield region, source, drain, the present invention can improve the performance of the third quadrant of SiC MOSFET, realize low reverse turn-on voltage and conduction loss and avoid the problem of bipolar degradation, when the device is turned off, the bottom P The ‑shield area can not only shield the electric field at the chamfer of the groove gate, but also protect the integrated Schottky interface at the bottom of the groove, effectively suppressing the excessive electric field at these two places, and improving the overall electrical characteristics and reliability of the device. Compared with traditional The structural channel is pinched off, and a JFET pinch is formed between the P-shield regions of adjacent cells of the device, and the Schottky contact electrode can also provide auxiliary depletion, so the structure has better short-circuit capability.

Description

technical field [0001] The invention belongs to the field of electronic science and technology, and mainly relates to the technology of power semiconductor devices, in particular to a Schottky contact SiC MOSFET device at the bottom of a groove. Background technique [0002] The wide bandgap semiconductor material SiC is an ideal material for preparing high-voltage power electronic devices. Compared with Si materials, SiC materials have a high breakdown electric field strength (4×10 6 V / cm), high carrier saturation drift velocity (2×10 7 cm / s), high thermal conductivity (490W / Mk), good thermal stability, etc., so it is especially suitable for high-power, high-voltage, high-temperature and radiation-resistant electronic devices. [0003] MOSFET is the most widely used device structure in SiC power devices. Compared with bipolar devices, SiC MOSFET has lower switching loss and higher frequency characteristics because it has no charge storage effect. [0004] Due to the poor ...

AI Technical Summary

Problems solved by technology

[0007] In order to optimize the performance of the third quadrant of SiC MOSFET devices and avoid bipolar degradation, and at the same time avoid the problem of excessive leakage current in the blocking state caused by the integration of the integrated Schottky interface electric field, the present invention proposes an integrated Schottky at the bottom of the groove. Diode-based SiC MOSFET devices

Images