Semiconductor structure and forming method thereof

Abstract

The invention discloses a semiconductor structure and a forming method thereof. The forming method comprises the steps of providing a substrate; forming a mask layer on the substrate; forming a compensation side wall on the side wall of the mask layer; etching the base by taking the mask layer and the compensation side wall as masks to form a substrate and fin parts protruding out of the substrate; removing the compensation side wall; and after the compensation side wall is removed, forming an isolation layer covering part of the side wall of the fin part on the substrate exposed out of the fin part. After the fin parts are formed, the compensation side walls are removed, then the isolation layer is formed, the process of forming the isolation layer comprises the step of filling the space between the fin parts with the isolation material layer, the size of the top opening of the opening defined by the mask layer, the fin parts and the substrate is large by removing the compensation side walls, and therefore in the process of depositing the isolation material layer, the bottom of the opening is easily filled with the isolation material layer, so the probability of accumulation of the isolation material layer at the top of the fin part is reduced, the extrusion force of the isolation material layer on the fin part is reduced, the problem of fin part bending is improved, and the performance of the semiconductor structure is improved.

Description

technical field [0001] Embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular, to a semiconductor structure and a method for forming the same. Background technique [0002] In semiconductor manufacturing, with the development trend of VLSI, the feature size of integrated circuits continues to decrease. In order to accommodate the reduction in feature size, the channel length of MOSFETs has also been shortened accordingly. 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. Difficulty is also increasing, making the phenomenon of subthreshold leakage (subthreshold leakage), the so-called short-channel effects (short-channel effects, SCE) more likely to occur. [0003] Therefore, in order to better adapt to the reduction of the fea...

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Problems solved by technology

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 effects (short-channel effects, SCE) more prone to occur

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