Fin field effect transistor and formation method thereof

Abstract

The invention provides a fin field effect transistor and a formation method thereof. The method comprises a step of providing a semiconductor substrate, wherein the surface of the semiconductor substrate is provided with a first fin and a second fin, the first fin comprises a second sub fin and a first sub fin at the top of the second sub fin, the second fin comprises a fourth sub fin and a third sub fin at the top of the fourth sub fin, a step of forming a first side wall at the side wall of the second sub fin, a step of forming a second side wall at the side wall of the third sub fin, a step of forming silicon germanium layers at the side walls of the first fin and the second fin, wherein the silicon germanium layers cover the first side wall and the second side wall, a step of carrying out oxidation processing on the silicon germanium layers such that the germanium atoms in the silicon germanium layers enter into the first sub fin and the fourth sub fin, and a step of orderly removing the silicon germanium layers, the first side wall and the second side wall after the oxidation processing. According to the method, the performance of the fin field effect transistor is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a fin field effect transistor and a forming method thereof. Background technique [0002] MOS transistors are one of the most important components in modern integrated circuits. The basic structure of a MOS transistor includes: a semiconductor substrate; a gate structure located on the surface of the semiconductor substrate, a source region located in the semiconductor substrate on one side of the gate structure, and a drain region located in the semiconductor substrate on the other side of the gate structure. The working principle of the MOS transistor is: by applying a voltage to the gate, the current through the channel at the bottom of the gate structure is adjusted to generate a switching signal. [0003] With the development of semiconductor technology, the ability of the traditional planar MOS transistor to control the channel current becomes weaker, resulting i...

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Problems solved by technology

[0005] The problem to be solved by the present invention is to provide a fin field effect transistor and its forming method to solve the problem of low carrier mobility in the fin field effect transistor, so as to improve the performance of the fin field effect transistor

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