Semiconductor structures and methods of forming them

Abstract

A semiconductor structure and a method for forming the same, the method comprising: providing a substrate; forming an interlayer dielectric layer on the substrate; forming an opening exposing the substrate in the interlayer dielectric layer; forming a gate dielectric layer on the bottom and side walls of the opening; The layer deposition process performs at least one film formation process to form an aluminum-containing work function layer on the gate dielectric layer. When the number of film formation processes is one, the number of pulses of the aluminum-containing precursor in the film formation process is at least 2 times, when the number of film formation processes is greater than 1, at least the number of pulses of the aluminum-containing precursor in the first film formation process is at least 2; a metal gate is formed in the opening for forming the active function layer. By increasing the number of pulses of the aluminum-containing precursor, especially the number of pulses in the first film formation process, to increase the content of aluminum atoms in the opening, improve the deposition ability of aluminum atoms in the opening, thereby increasing the aluminum content of the work function layer Atomic content, thereby improving the threshold voltage flipping problem of transistors.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, 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...

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Problems solved by technology

[0005] In the prior art, the adjustment of the threshold voltage of the transistor is realized by forming a work function layer in the gate structure of the transistor, but the transistor with the work function layer still has the problem of poor electrical performance, resulting in poor performance of the formed semiconductor structure

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