Forming method for semiconductor trench structure

Abstract

The invention provides a forming method for a semiconductor trench structure. The forming method for the semiconductor trench structure comprises the steps of supplying a semiconductor substrate, and forming a first medium layer and a second medium layer in sequence on the semiconductor substrate; removing part of the second medium layer to form a first window; executing an oxidization technology to form a beak structure in the first window; etching the beak structure in the first window and the semiconductor substrate below the beak structure to form a second window; removing the second medium layer and the first medium layer to form a third window; performing repairing layer growth on the surfaces of the third window and the semiconductor substrate, and then removing the grew repairing layers to form trenches; forming oxidized layers on the trenches and the surface of the semiconductor substrate. Due to the beak structure, the smooth trenches with good appearances can be obtained, so that the oxidized layers with uniform thicknesses can be obtained in the trenches; therefore, the characteristic of a semiconductor device is improved, and the stability and the reliability of the semiconductor device are guaranteed.

Description

technical field [0001] The invention relates to the technical field of integrated circuit manufacturing, in particular to a method for forming a semiconductor trench structure. Background technique [0002] Power devices can be divided into power integrated circuit (IC) devices and power discrete devices. Among them, power discrete devices include power MOSFETs, high-power transistors and IGBTs. Early power devices were produced based on planar technology, but with the development of semiconductor technology, small size, high power, and high performance have become the development trend of semiconductor devices. However, taking planar technology MOSFET devices as an example, due to the limitation of the parasitic resistance of the JFET in the body, the area of ​​a single cell is limited, which makes it difficult to increase the density of the original cells, and cannot make the on-resistance RDSON of the planar technology MOSFET further reduced. The trench technology chang...

AI Technical Summary

Problems solved by technology

[0011] The purpose of the present invention is to provide a method for forming a semiconductor trench structure to solve the problem that the existing trench has poor morphology and obvious protrusions on the top, which leads to the unevenness of the formed oxide layer

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