Semiconductor device and forming method thereof

Abstract

The invention discloses a semiconductor device and a forming method thereof. The method comprises the steps: providing a substrate, wherein the substrate has a pseudo-gate dielectric film; forming a pseudo-gate structure on the pseudo-gate dielectric film, wherein the pseudo-gate structure comprises a pseudo-gate electrode layer and sacrifice side walls located on the side walls of the pseudo-gateelectrode layer; removing a part of the pseudo-gate dielectric film at the two sides of the pseudo-gate structure until the surface of the substrate is exposed, and forming a pseudo-gate dielectric layer at the bottom of the pseudo-gate structure; after the pseudo-gate dielectric layer is formed, removing the sacrifice side walls; after the sacrifice side walls are removed, forming a side wall structure on the side wall of the pseudo-gate electrode layer and the side wall of the pseudo-gate dielectric layer; and forming openings in the substrate at the two sides of the pseudo-gate electrode layer and the side wall structure. The semiconductor device formed by the method is good in performance.

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] With the rapid development of integrated circuit manufacturing technology, the size of semiconductor devices in the integrated circuit is continuously reduced, so that the operation speed of the entire integrated circuit will be effectively improved. However, when the size of the device is further reduced, in the case of a fin field effect transistor, the resistance and parasitic resistance of the gate and source / drain will increase accordingly, which will reduce the overall effect of the device reduction. Improvement of circuit performance is hindered. [0003] At present, the industry applies the selective epitaxial growth process to the semiconductor process to overcome the above-mentioned problems. [0004] However, before the epitaxial process is used to form the source and drain r...

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Problems solved by technology

[0004] However, before the epitaxial process is used to form the source and drain regions, an epitaxial cleaning process is usually performed to completely remove impurities on the substrate surface. The epitaxial cleaning process will cause over-etching of the oxide layer on the substrate surface, resulting in the subsequent formation of semiconductor poor device performance

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