Method for Improving the Stability of Polysilicon Gate Etching Process

Abstract

The present invention provides a method for improving the stability of the etching process of a polycrystalline silicon gate. The method comprises: providing a semiconductor substrate, and forming a gate oxide on the semiconductor substrate; forming an oxide layer on the gate oxide; coating the oxide layer with a player of photoresist, and after etching, removing the oxide layer in the area of the polycrystalline silicon gate and removing the photoresist; growing a polycrystalline silicon layer on the semiconductor substrate; and after photolithography and etching, forming the polycrystalline silicon gate in the polycrystalline silicon layer. According to the method provided by the invention, in the process of etching the polycrystalline silicon gate, damage on the active region caused by insufficiency of the etching selectivity ratio of the polycrystalline silicon gate and the gate oxide is prevented by the oxide layer, so that the stability of the etching process of the polycrystalline silicon gate and the electrical performance of the product are improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for improving the stability of a polysilicon gate etching process. Background technique [0002] With the development of semiconductor technology, the size of semiconductor devices is getting smaller and smaller, especially in the process of 65nm and below, in order to meet the electrical requirements, the gate oxide layer becomes thinner and thinner, and the etching of polysilicon gate Process requirements are getting higher and higher. [0003] Such as Figure 1-6 as shown, figure 1 is a schematic flow chart of a conventional polysilicon gate etching method, Figure 2-6 A schematic diagram of a cross-sectional structure formed by each preparation step of a conventional polysilicon gate etching method, including: [0004] Step S11: See figure 2 , providing a semiconductor substrate 101, forming a gate oxide layer 102 on the semiconductor substr...

AI Technical Summary

Problems solved by technology

[0011] In order to overcome the above problems, the purpose of the present invention is to avoid the phenomenon that the active region is damaged due to the insufficient etching selectivity ratio of the polysilicon gate and the gate oxide layer, thereby further improving the stability of the polysilicon etching process

Images