Semiconductor structure and manufacturing method thereof

Abstract

The invention relates to a semiconductor structure and a manufacturing method thereof. The method comprises the steps of forming a substrate and a second fin part, wherein the substrate comprises a second region, the second fin part protrudes out of the substrate; forming a second pseudo gate structure on the second fin part, wherein the second pseudo gate structure comprises a pseudo gate oxide layer and a second pseudo gate electrode layer; forming a side wall layer on a surface of a side wall of the second pseudo gate structure; oxidizing the second pseudo gate structure; forming a dielectric layer on the substrate; removing the second pseudo gate electrode layer, and forming a second opening in the dielectric layer; removing the pseudo gate oxide layer; and filling the second opening with a metal layer to form a second gate structure. Due to a shading effect of the side wall layer, a side wall oxide layer is not liable to form on the side wall of the second pseudo gate structure by oxidization processing, so that the process of the pseudo gate oxide layer is removed, the side wall oxide layer is also removed, the size of the second opening is further prevented from being increased, the problems that a contact hole is blocked and short circuit occurs in the second gate structure caused by excessively small distance between the metal layer and a source region and a drain region at two sides of the second gate structure are prevented, and the electrochemical performance of a semiconductor device is improved.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a semiconductor structure and a manufacturing method thereof. Background technique [0002] In semiconductor manufacturing, with the development trend of VLSI, the feature size of integrated circuits continues to decrease. In order to adapt to the reduction of feature size, the channel length of MOSFET devices is also continuously shortened. However, as the channel length of the device is shortened, the distance between the source and the drain of the device is also shortened, so the control ability of the gate to the channel becomes worse, and the gate voltage pinches off the channel. The difficulty is also increasing, making the phenomenon of subthreshold leakage (subthreshold leakage), the so-called short-channel effect (SCE: short-channel effects) more likely to occur. [0003] Therefore, in order to better adapt to the reduction of the feature size, the semiconductor process ...

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Problems solved by technology

[0006] However, the electrical performance of the semiconductor device formed by the prior art is poor

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