Semiconductor and formation method thereof

Abstract

The invention relates to a semiconductor structure and a formation method thereof. The formation method comprises the following steps: providing a substrate, wherein the substrate comprises a device area and an isolation area which are adjacent, discrete fin parts are formed on the substrate, and distances between every two adjacent fin parts are equal; forming a protective layer on the side wallof each fin part; etching and removing the protective layer with partial thickness and part of fin parts in the isolation area by adopting a first etching technology; taking the rest of the protectivelayers as a mask, etching the rest of the fin parts in the isolation area by adopting a second etching technology, and forming pseudo fin parts; after the second etching technology is carried out, removing the rest of the protective layers; and after the rest of the protective layers are removed, forming an isolation structure on the substrate, wherein the top of the isolation structure is lowerthan the top of the fin parts in the device area and is higher than the top of the pseudo fin parts. The formation method divides a step of etching the fin parts in the isolation area into two steps,thus the size of an etching process window for removing the fin parts in the isolation area can be increased, and etching damage on adjacent fin parts in the device area is reduced.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a semiconductor structure and a forming method thereof. Background technique [0002] In the field of 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 field effect transistors is also continuously 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. 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 reductio...

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Problems solved by technology

[0004] However, the electrical performance of prior art semiconductor structures needs to be improved

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