Method for improving gate-source electric leakage of trench-type metal oxide semiconductor

Abstract

The invention discloses a method for improving gate-source electric leakage of a trench-type metal oxide semiconductor. According to the invention, a gate oxide layer on the side wall of a trench is prevented from being damaged twice due to P-type impurity body region injection and N-type impurity source region injection, the gate oxide layer on the side wall of the trench is good in quality, a good gate and source isolation effect is achieved, the gate-source electric leakage of the equipment is improved, equipment quality reduction and equipment failure caused by gate-source electric leakageare avoided, and good market application value is achieved.

Description

technical field [0001] The invention relates to the field of semiconductor chip manufacturing, in particular to a method for improving gate-source leakage of trench-type metal oxide semiconductors. Background technique [0002] Double-diffused metal-oxide-semiconductor (DMOS) transistors combine the advantages of bipolar transistors and ordinary metal-oxide (MOS) devices. Regardless of switching applications or linear applications, DMOS is an ideal power device. DMOS is mainly used in inverters, electronic switches, hi-fi audio, automotive electrical appliances and electronic ballasts, etc. [0003] DMOS is divided into planar DMOS and trench DMOS. Planar DMOS is mainly developed in the direction of high voltage, while trench DMOS is mainly developed in the direction of medium and low voltage. The two are constantly changing and developing and innovating with the application environment. The performance requirements are becoming more and more stringent, and a key parameter ...

AI Technical Summary

Problems solved by technology

[0015] For DMOS devices, the gate oxide layer acts as an isolation between the gate and the source, and its quality directly affects the size of the gate-source leakage. In the existing trench-type DMOS processing technology, the gate After the oxide layer grows, the gate oxide layer on the side wall of the trench is exposed on the surface, and it will be damaged by the subsequent two bombardments of the P-type body region ion implantation and the source region ion implantation, although in the subsequent thermal process It will be repaired, but it is difficult to completely repair or return to the state that has not been bombarded by ions, thus affecting the integrity of the quality of the gate oxide layer, causing the isolation effect of the gate and source to deteriorate, and often causing gate-source leakage bias large lead to product quality reduction or product failure, therefore, the problem of large gate-source leakage urgently needs to be improved as soon as possible

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