A high-reliability SiC MOSFET device

Abstract

The invention provides a high-reliability SiC MOSFET device, comprising an N-type substrate, an N-type epitaxial layer, a P-Body region, a P + contact region, an N + contact region, an oxide layer, agate electrode, a Schottky contact electrode, a deep P-Well, a deep P-well region ; The right side of the oxide layer, the right side of the Schottky contact electrode and part of the lower side of the Schottky contact electrode are tightly wrapped; The invention can improve the performance of the third quadrant of the SiC MOSFET, realizes low reverse turn-on voltage and conduction loss, avoids the problem of bipolar degradation, The P-well region can not only shield the electric field at the chamfer of the groove gate, but also protect the Schottky interface at the bottom of the groove, whichcan effectively restrain the phenomenon of excessive electric field at the two places, and improve the overall electrical characteristics and reliability of the device. JFET pinch-off is also formedbetween adjacent cell deep P-well regions , and Schottky contact electrodes can also provide auxiliary depletion, so the structure has better short-circuiting capability.

Description

technical field [0001] The invention belongs to the field of electronic science and technology, and mainly relates to power semiconductor device technology, in particular to a high-reliability SiC MOSFET device. 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 interface state of the current SiC...

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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

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