Method for manufacturing semiconductor device

Abstract

The invention relates to a method for manufacturing a semiconductor device, comprising the steps of: a) providing a substrate, forming a gate dielectric layer on the substrate, forming a dummy gate on the gate dielectric layer, and forming an etch stop layer covering the gate dielectric layer and the dummy gate; b) forming a pre-metal dielectric layer on a front-end device layer structure; c) planarizing the pre-metal dielectric layer until the upper surface of the dummy gate is exposed; d) removing the dummy gate to form an opening for accommodating a metal gate; e) forming a photoresist layer within the opening and on the surface of the pre-metal dielectric layer; f) planarizing the photoresist layer and the protruding etch stop layer; g) removing the photoresist layer within the opening; and h) forming a metal gate within the opening. The method, after the dummy gate is removed, can help effectively reduce dishing phenomenon in dense areas, overcome the defects caused by residue of metal used for forming gates and reduction on the thickness of gates, and improve performance of semiconductor devices.

Description

technical field [0001] The present invention relates to a semiconductor manufacturing process, and more particularly, the present invention relates to a method of manufacturing a semiconductor device with a metal gate. 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 (CD) on the wafer, so the fabrication of the gate is one of the most critical steps in the process of semiconductor device manufacturing. [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 a relatively high resistance value, which is prone to depletion effect and boron penetration int...

AI Technical Summary

Problems solved by technology

This will have a great impact on the subsequent process, such as causing an increase in leakage current, etc.

More importantly, it will cause the metal used to form the metal gate to remain in the recess when the metal is filled in the subsequent process to form the metal gate.

In the prior art, an over polishing process is usually used to remove the residual metal in the recess, but it will bring a series of problems such as the reduction of the thickness of the metal gate and the dishing of the surface of the metal gate.

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