Formation method of semiconductor structure

Abstract

A method for forming a semiconductor structure, comprising: providing a substrate; forming a work function layer on the substrate, the step of forming the work function layer includes one or more steps of forming a work function film, and the step of forming the work function film includes: An initial work function film is formed on the substrate, and the initial work function film has carbon atoms; the carbon removal precursor is used to remove carbon from the initial work function film to form a work function film, and the carbon removal precursor is used to interact with The carbon atoms in the initial work function film react; a gate is formed on the work function layer. A gate is formed on the work function layer. After the initial work function film is formed, the carbon removal treatment is performed on the initial work function film through the carbon removal precursor. The carbon-removing precursor can react with the carbon atoms in the initial work function film, thereby reducing the carbon atom content in the initial work function film, thereby changing the work function of the work function layer, and then adjusting the threshold voltage of the formed transistor, so that all The threshold voltage of the formed transistor meets the design requirements.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for forming a semiconductor structure. Background technique [0002] With the continuous progress of semiconductor technology, the integration level of semiconductor devices has been continuously improved, which requires that more transistors can be formed on a chip. [0003] Threshold voltage is an important parameter of transistors, which has a great influence on the performance of transistors. Transistors with different functions often have different requirements on threshold voltages. During the process of forming different transistors, the threshold voltages of different transistors need to be adjusted. In order to adjust the threshold voltages of different transistors, a work function layer is often formed on the surface of the gate dielectric layer of the transistor. Transistors can have different threshold voltages by selecting the thickness and mater...

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Problems solved by technology

[0004] However, the threshold voltage of the transistor formed by the prior art is difficult to meet the design requirements

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