Method for producing semiconductor device

Abstract

The invention provides a method for producing a semiconductor device. The method comprises the following steps of: providing a substrate; forming a polycrystalline silicon layer on the surface of the substrate; forming a mask layer on the surface of the polycrystalline silicon layer; patterning the mask layer and the polycrystalline silicon layer to form a polycrystalline silicon grid and a barrier layer which is located on the surface of the polycrystalline silicon grid; and producing side walls at two sides of the polycrystalline silicon grid; doping at two sides of the polycrystalline silicon grid to form a source electrode and a drain electrode; forming self aligned polycide layers on the surface of the substrate and the surface of the barrier layer; forming interlayer dielectric layers on the surfaces of the polycide layers and the surfaces of the side walls; removing the interlayer dielectric layers to the polycrystalline silicon grid by a chemical and mechanical grinding method; removing the polycrystalline silicon grid to form a groove for obtaining a metal grid; and doping in the groove to form the metal grid. According to the method provided by the invention, etching speeds of different polycrystalline silicon grids are basically the same and the etching effect is guaranteed, so that the quality of the subsequently formed metal grid is ensured.

Description

technical field [0001] The present invention relates to semiconductor fabrication processes, and more particularly, the present invention relates to a method of fabricating a semiconductor device. Background technique [0002] The gate usually has the smallest physical dimension in the semiconductor manufacturing process, and its width is usually the most critical critical dimension on the wafer, so the fabrication of the gate is the most critical step in the process in the semiconductor device manufacturing process. [0003] Because polysilicon material has the advantages of high temperature resistance and the ability to prevent atoms doped by ion implantation from entering the channel region, polysilicon material is usually used to make the gate of the transistor when making a typical metal oxide semiconductor transistor. However, the polysilicon gate has some disadvantages. For example, the polysilicon gate has a relatively high resistance value, which is prone to depleti...

AI Technical Summary

Problems solved by technology

[0005] In the above process, since the self-aligned polysilicon layer is directly formed on the surface of the polysilicon gate, the two will react after contact to generate some silicide residual defects, and because the degree of reaction at different polysilicon gates is different, Therefore, the residual silicide defects generated by the reaction have different depths in different polysilicon gates

In this case, when polishing the interlayer dielectric layer, these residual defects may not be completely removed, so that different depths of silicide residual defects remain in different polysilicon gates

In this way, due to the different etching speeds of different materials, when multiple polysilicon gates with residual silicide defects are etched simultaneously, different polysilicon gates of the same wafer will be etched to different depths, which may cause Some polysilicon gates are etched incompletely or may even destroy the gate oxide layer, which eventually leads to defects when making metal gates

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