Semiconductor device and method for forming same

Abstract

The invention provides a semiconductor device and a method for forming the same. The semiconductor device comprises a substrate, a first interlayer dielectric layer, a metal grid, side walls, a second interlayer dielectric layer and a conductive plug, wherein the first interlayer dielectric layer is positioned on the substrate; the metal grid is positioned on the substrate and is formed in the first interlayer dielectric layer; the side walls are positioned on the substrate and are arranged on two sides of the metal grid; the second interlayer dielectric layer is positioned on the first interlayer dielectric layer and covers the metal grid and the side walls; the conductive plug is positioned in the second interlayer dielectric layer; and a protecting layer is arranged between the metal grid and the second interlayer dielectric layer and is communicated with the conductive plug. The phenomenon that the surface conductivity of the metal grid becomes poor so that the resistance of the conductive plug connected with the metal grid is reduced is effectively prevented, and the reliability and the electrical property of the semiconductor device are improved.

Description

technical field [0001] The invention relates to the field of semiconductor technology, in particular to a semiconductor device including a metal gate and a forming method thereof. Background technique [0002] With the continuous improvement of the integration level of semiconductor devices and the reduction of technology nodes, the traditional gate dielectric layer continues to become thinner, and the leakage of transistors increases accordingly, causing problems such as waste of power consumption of semiconductor devices. In order to solve the above problems, the prior art provides a solution of replacing the polysilicon gate with a metal gate. Among them, the "gate last" process is a main process for forming the metal gate. [0003] In U.S. Patent No. 6,664,195, a method for forming a semiconductor device including a metal gate using a "gate-last" process is provided, including: providing a semiconductor substrate on which a replacement gate structure is formed and locat...

AI Technical Summary

Problems solved by technology

[0004] In practical applications, it is found that the top of the metal gate in the semiconductor device formed by the above technical solution is easily oxidized, resulting in poor conductivity of the surface of the metal gate, which in turn increases the resistance of the conductive plug connected to the metal gate.

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