Semiconductor structures and methods of forming them

Abstract

The invention discloses a semiconductor structure and a forming method therefor, and the method comprises the steps: providing a substrate; forming metal gate structures on the substrate on the substrate, wherein each metal gate structure comprise a gate dielectric layer, a work function layer located on the gate dielectric layer, and a metal layer located on the work function layer; forming a barrier layer at the tops of the metal gate structures; forming an interlayer dielectric layer on the substrate between the metal gate structures; forming a contact hole plug passing through the interlayer dielectric layer; and carrying out the annealing treatment of the substrate after the forming of the contact hole plug. After the forming of the metal gate structures, the barrier layer is formed at the tops of the metal gate structures. The barrier layer is used for protecting the metal gate structures in the subsequent annealing treatment, and prevents the atoms liable to diffuse in the annealing treatment to diffuse to the work function layers of the metal gate structures, thereby avoiding the impact on the work function values of the work function layers, and achieving optimization of the electrical performances of a semiconductor device.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a semiconductor structure and a forming method thereof. Background technique [0002] The main semiconductor device of an integrated circuit, especially a very large scale integrated circuit, is a metal-oxide-semiconductor field effect transistor (MOS transistor). With the continuous development of integrated circuit manufacturing technology, the technology nodes of semiconductor devices continue to decrease, and the geometric dimensions of semiconductor devices follow Moore's law. When the size of semiconductor devices is reduced to a certain extent, various secondary effects caused by the physical limits of semiconductor devices appear one after another, and it becomes more and more difficult to scale down the feature size of semiconductor devices. Among them, in the field of semiconductor manufacturing, the most challenging thing is how to solve the problem of large leakage curr...

AI Technical Summary

Problems solved by technology

[0004] Although the introduction of high-k metal gates can improve the electrical performance of semiconductor devices to a certain extent, the electrical performance of semiconductor devices formed in the prior art needs to be improved

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