Forming method of high-voltage super-junction metal oxide semiconductor field effect transistor (MOSFET) structure and P-shaped drift region

Abstract

The invention provides a forming method of a high-voltage super-junction metal oxide semiconductor field effect transistor (MOSFET) structure and a P-shaped drift region, which includes the following steps: providing a semiconductor substrate and growing a first N-shaped epitaxial layer on the semiconductor substrate; injecting boron ions to the first N-shaped epitaxial layer to form a boron injection area; growing a second N-shaped epitaxial layer and an oxidation film on the first N-shaped epitaxial layer with injected ions from the bottom to the top sequentially; etching the oxidation film and the second N-shaped epitaxial layer sequentially, forming a groove at the position corresponding to a boron injection area, and stopping etching on the first N-shaped epitaxial layer; conducting inclined injection on a lateral wall of the groove to form a mixing layer; removing the oxidation film and growing a third N-shaped epitaxial layer on the second N-shaped epitaxial layer and in the groove; and conducting annealing technology on the structure to form the P-shaped drift region. By means of technology of combining epitaxy and the groove, on the basis of reducing connection resistance and improving breakdown voltage remarkably, technology is simplified, technology difficulty is reduced, and mass production is facilitated.

Description

technical field [0001] The invention belongs to the field of power semiconductor device manufacturing, and in particular relates to a method for forming a P-type drift region of a super-junction MOSFET and a super-junction MOSFET structure formed with a P-type drift region. Background technique [0002] Power semiconductor devices are always developing towards large power control capacity (high voltage and high current) and high speed. Among high-voltage MOS devices in power integrated circuits, since vertical double-diffused metal-oxide-semiconductor field-effect transistors (VDMOS) have the advantages of both bipolar transistors and ordinary MOS devices, VDMOS is ideal for both switching applications and linear applications. device. [0003] On-resistance (RON) is an important indicator to measure the performance of VDMOS. According to the direction of the conductive channel relative to the surface of the silicon wafer, VDMOS technology can be roughly divided into two ca...

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Problems solved by technology

On the other hand, there are still problems in the actual implementation process, and it is urgent to introduce new methods that can effectively improve the above-mentioned defects to solve the main problems of the existing P-type drift region formation, such as high cost and complicated process.

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