Method and device for improving withstand voltage of trench type power tube terminal

Abstract

The invention relates to a method and device for improving terminal withstand voltage of a groove type power tube, and the method comprises the steps: making a primary sacrificial oxide layer through a furnace tube technology after the etching and cleaning of a groove are completed, specifically, covering a unit cell region through a photoetching technology, and opening a terminal region through development; etching the sacrificial oxide layer at the bottom of the trench in the terminal region by using a dry etching process; etching off the silicon which is not protected by the sacrificial oxide layer at the bottom of the trench in the terminal region by using a wet etching process; removing the photoresist on the wafer by using an etching process; the breakdown voltage of the power tube can be greatly improved under the condition that the resistance performance of the groove type power tube is not affected, and the overall performance of the power tube is improved. Compared with the prior art, although the process steps are increased, the breakdown voltage of the terminal can be greatly improved, so that the performance parameters of the device are not limited by the breakdown voltage of the terminal any more.

Description

technical field [0001] The invention relates to the application field of electronic semiconductor devices, in particular to a method and a device for improving the withstand voltage of a trench-type power tube terminal. Background technique [0002] Power MOS transistor is a specific type of MOS transistor that provides and switches power in integrated circuits. It not only inherits the advantages of MOS field effect transistors, but also has high withstand voltage, large operating current, high output power, and fast switching speed. Excellent characteristics. It is precisely because it combines the advantages of electron tubes and power transistors that it is widely used in switching power supplies, inverters, voltage amplifiers, power amplifiers and other circuits. [0003] In order to reduce the size of power MOS transistors, trench MOS (trench MOS) transistors are currently introduced. The channel of the trench power MOS transistor is vertical, so the channel density ...

AI Technical Summary

Problems solved by technology

The shape of the existing groove is an inverted trapezoid, the bottom is smaller, the electric field will be more concentrated, and the voltage will easily break down

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