Power semiconductor device and manufacturing method thereof

Abstract

The application discloses a power semiconductor device and a manufacturing method thereof. The method herein includes the following steps: forming an epitaxial layer on a first surface of a semiconductor substrate, wherein the semiconductor substrate and the epitaxial layer are both of a first doping type and separately have a first doping concentration and a second doping concentration; forming a gate stack on the epitaxial layer, wherein the gate stack includes a gate medium layer and a gate conductor, and the gate medium layer is sandwiched between the gate conductor and the epitaxial layer; forming a body region in the epitaxial layer, wherein the body region is a second doping type; forming a first doping region in the body region, wherein the first doping region is the first doping type; forming a first contact which reaches the first doping region; doping the semiconductor substrate by beginning from a second surface of the semiconductor substrate so as to increase doping concentration; and forming a second contact on the second surface of the semiconductor substrate, wherein the first doping concentration is 5-100 times of the second doping concentration. The method herein reduces the concentration difference between the semiconductor substrate and the epitaxial layer in the process, thus reducing the thickness of a transition region and increasing product qualification rate.

Description

technical field [0001] The present invention relates to semiconductor devices, and more particularly, to power semiconductor devices and methods of manufacturing the same. Background technique [0002] Power semiconductor devices are widely used in electronic equipment, for example, as amplifying transistors in power amplifier circuits or as switching transistors in power supply circuits. Power semiconductor devices include bipolar transistors, metal oxide semiconductor transistors (MOSFETs), insulated gate bipolar transistors (IGBTs), and the like. [0003] MOSFET devices have developed multiple generations of products since the 1960s. A conventional MOSFET device includes an epitaxial layer grown on a semiconductor substrate, in which source and drain regions are formed, and a gate stack formed above the epitaxial layer. The thickness and concentration of the epitaxial layer determine the withstand voltage and on-resistance Rds(on) of the MOSFET device. The thicker the ...

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Problems solved by technology

Because the thickness of the epitaxial layer is too thick, the processing efficiency of the epitaxial layer is low and difficult. During the process of high-thickness epitaxial growth, many defects and serious warping will be formed on the edge of the wafer, and there will be a high fragmentation rate in the subsequent production process.

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