High-avalanche capability power semiconductor transistor structure and preparation method thereof

Abstract

The invention provides a high-avalanche capability power semiconductor transistor structure, which comprises an N-type substrate used as a drain region, wherein an N-type epitaxial layer is arranged on the N-type substrate; P-type strip body regions are arranged on the surface of the N-type epitaxial layer; a heavily doped N-type source region and a heavily doped P-type source region are arranged on the surface of each P-type strip body region; an insulated gate oxidation layer is arranged on the N-type epitaxial layer; conductive polysilicon is arranged on the insulated gate oxidation layer, and is located at the upper part of the region between the adjacent P-type strip body regions and two sides of the conductive polysilicon respectively cover the adjacent P-type strip body regions; an insulated medium layer is arranged on the conductive polysilicon; the heavily doped N-type source regions and the heavily doped N-type source regions are connected with a source metal; the high-avalanche capability power semiconductor transistor structure is characterized in that the P-type strip body regions extend towards the N-type epitaxial layer to form a plurality of P-type arched body regions; and the P-type arched body regions are evenly distributed on the P-type strip body regions and are embedded into the N-type epitaxial layer. According to the high-avalanche capability power semiconductor transistor structure, a preparation method of a traditional power semiconductor transistor is reserved; the avalanche capability is improved; the chip area is reduced; and the cost is relatively low.

Description

technical field [0001] The invention mainly relates to the technical field of power semiconductor devices, in particular to a power semiconductor transistor with high avalanche tolerance and a preparation method thereof, especially suitable for electric vehicles, motor speed regulation, inverters, uninterruptible power supplies, electronic switches, high-fidelity audio, automobiles Electrical and electronic rectifiers. Background technique [0002] The vertical double-diffused metal-oxide semiconductor field-effect transistor has the advantages of both bipolar transistors and ordinary metal-oxide semiconductor field-effect transistor devices. It is an ideal power device for both switching applications and linear applications, because it has nearly infinite Large static input impedance characteristics, very fast switching time, positive temperature coefficient of on-resistance, approximately constant transconductance, extremely fast voltage reversal speed and other characteri...

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Problems solved by technology

[0004] In order to improve the avalanche tolerance of the device, the current common practice is to increase the device’s ability to pass a large current by increasing the area of ​​the device, but the manufacturing cost of the device increases; or change the doping concentration of the region related to the avalanche tolerance of the device , this can theoretically improve the avalanche tolerance, but after the doping concentration increases, the fluctuation of the process preparation will increase, and some P-type impurity concentration peaks will be generated at the bottom of the P-type body region, which will easily lead to the deterioration of the breakdown uniformity. Reduced avalanche tolerance and reduced yield

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