SiC MOSFET device with integrated schottky diode

Abstract

The invention discloses a SiC MOSFET device with an integrated schottky diode, wherein an original cell structure of a source region from top to bottom is a drain electrode, a substratum, a buffer layer, a drift layer and two P well regions symmetrically from the left and the right. The adjacent n++ area and P++ area arranged on the P well regions from left to right are sequentially provided with a source electrode, a grid electrode, a schottky metal, the grid electrode and the source electrode. The source electrode is positioned above the n++ area and P++ area. The surface part of the P well regions is fully covered with the grid electrode. One side of the grid electrode overlaps with the n++ area and the other side of the grid electrode overlaps with a JFET area. The schottky metal is positioned above the JFET area. The SiC MOSFET device with the integrated and inverse parallel schottky diode is provided, wherein the integrated schottky diode is located in the JFET area, adjacent to the grid electrode area. The SiC MOSFET device with higher original cell integration and density has the advantage of effectively utilizing the proportion of the JFET area. Meanwhile, compared with conventional MOSFET, the current MOSFET is capable of effectively reducing grid capacitance and input-output capacitance and improving switching performance of the device due to the area reduction of the gate capacitance.

Description

technical field [0001] The invention belongs to the field of semiconductors, and in particular relates to a SiC MOSFET device integrating Schottky diodes. Background technique [0002] SiC MOSFET After years of research in the industry, some manufacturers have taken the lead in launching commercial products. In many applications, controllable devices such as transistors need to be anti-parallel with a freewheeling diode to work together. For example, the commonly used silicon IGBT modules are anti-parallel fast recovery diodes as freewheeling diodes. If a freewheeling diode is integrated in a device, it not only improves the integration level of the chip, but also effectively reduces the cost of the chip. [0003] In order to suppress the opening of the internal parasitic BJT in the structure of modern MOSFET devices, the source and the p-well are often electrically connected and short-circuited. Therefore, modern SiC MOSFET devices often have anti-parallel pn diodes thems...

AI Technical Summary

Problems solved by technology

The latest SiC MOSFET also integrates anti-parallel SBD in the device structure, and the integrated SBD is often made in the source region, such as the technical solution disclosed in US Patent US6979863, but the source metal is adjacent to the Schottky metal, and the corresponding original The cell area increases, which affects the device current density

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