Method for forming semiconductor structure

Abstract

A method for forming a semiconductor structure includes the following steps: forming a substrate which includes a first region and a second region; forming a dummy gate structure; forming an opening;forming a first gate dielectric layer and a second gate dielectric layer; forming a sacrificial layer; forming a first material layer; forming a first mask; exposing the second gate dielectric layer;exposing the first material layer; and forming a second material layer. Compared with the prior art in which the second gate dielectric layer is protected only by the first material layer, in the technical scheme of the invention, the first material layer and the sacrificial layer can better protect the second gate dielectric layer because of larger total thickness, the damage to the second gate dielectric layer in the forming process of the first mask can be effectively reduced, the performance of the gate dielectric layer can be improved, and the performance of a semiconductor structure formed can be improved.

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 rapid development of semiconductor manufacturing technology, semiconductor devices are developing towards higher element density and higher integration. As the most basic semiconductor device, transistors are currently being widely used. Therefore, with the improvement of component density and integration of semiconductor devices, the feature size of transistors is getting smaller and smaller. In order to reduce the parasitic capacitance of transistor gates and improve device speed, high The gate structure of the K gate dielectric layer and the metal gate is introduced into the transistor. [0003] However, there are still many problems to be solved when forming a metal gate on a high-K gate dielectric layer, one of which is the matching of the work function, because the work functio...

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Problems solved by technology

[0004] However, even with the introduction of a work function layer in the high-K metal gate structure, the performance of the semiconductor structure in the prior art still needs to be improved

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