Semiconductor device and method of forming the same

Abstract

The invention discloses a semiconductor device and a forming method thereof. The method comprises the following steps: providing a substrate, wherein a part of the substrate is provided with a gate structure film; forming a first side wall and a mask side wall, wherein two side walls of the gate structure film are covered with the first side wall respectively, the top surface of the first side wall is higher than the top surface of the gate structure film, the mask side wall is positioned on a part of the gate structure film, and the mask side wall is in contact with the first side wall higherthan the top surface of the gate structure film; using the first side wall and the mask side wall as masks to etch the gate structure film, and forming a gate structure with a first side and a secondside which are opposite, wherein the first side wall is positioned on the first side of the gate structure; forming second side walls on the first side and the second side of the gate structure respectively, wherein the second side wall on the first side of the gate structure is on the side wall surface of the first side wall, and the second side wall on the second side of the gate structure is on the side wall surface of the gate structure and the side wall surface of the mask side wall; and then correspondingly forming a drain region and a source region in the substrate on the first side and the second side of the gate structure respectively. According to the method, the process difficulty is reduced.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a semiconductor device 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. [0003] With the development of semiconductor technology, the ability of the traditional planar MOS transistor to control the channel current becomes weaker, resulting in serious leakage current. Fin Field Effect Transistor (Fin FET) is an emerging multi-gate device, which generally includes a fin protruding from the surface of the semiconductor substrate, and a gate s...

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Problems solved by technology

[0007] However, the process of forming the semiconductor device with asymmetric sidewall (symmetric drain spacer extension) is relatively difficult

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