U-shaped source-trough vdmosfet device with integrated schottky diode

Abstract

The present invention relates to the field of integrated circuits and disclosed thereby is a VDMOSFET device that has a U-type source groove and that integrates a Schottky diode, comprising a substrate (8); a drain electrode (9) that is disposed below the substrate (8); an N- drift region (7) that is disposed above the substrate (8); a source electrode (4) that is disposed above the N- drift region (7); an N+ source region (5) that is disposed in the N- drift region (7) at two sides of the source electrode (4); a P-type base region (6) that is disposed at the interior of the N- drift region (7); a gate source isolation layer (3) that is disposed above the N+ source region (5); a gate medium (2) and a gate electrode (10); the interface between the source electrode (4) and the N- drift region (7) is a Schottky contact. The device may improve the reliability of device performance and reduce the complexity and costs of design.

Description

technical field [0001] The invention relates to the technical field of microelectronics, in particular to a U-shaped source-trough VDMOSFET device integrating Schottky diodes. Background technique [0002] Silicon carbide, a wide bandgap semiconductor material, has a large band gap, a high critical breakdown electric field, and excellent physical and chemical properties such as high thermal conductivity and high electron saturation drift velocity. It is suitable for making high temperature, high pressure, high power, radiation resistant illuminated semiconductor devices. In the field of power electronics, power MOSFET has been widely used, it has the characteristics of simple gate drive and short switching time. [0003] In the existing VDMOSFET structure, in order to avoid turning on the parasitic NPN transistor, the P-type base region and the N+ source region are usually short-circuited by introducing a P+ ohmic contact region on the surface of the P-type base region. At...

AI Technical Summary

Problems solved by technology

At the same time, VDMOSFET is used as a power switch in the converter. When its body diode continues to flow forward current as a freewheeling path, the phenomenon of "power-on deterioration" will occur, which will increase the on-resistance and the forward conduction voltage drop of the diode. and cause reliability issues

Therefore, in practical applications, a Schottky diode with a turn-on voltage lower than the body diode is usually connected in parallel at both ends of the source and drain of the device to provide a freewheeling path and ensure that the body diode will not conduct. This method greatly increases reduce the complexity and cost of circuit design

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