Formation method of fin field effect transistor

Abstract

A formation method of a fin-type field-effect transistor is disclosed. The method comprises the following steps of providing a substrate including an effective area, first edge areas located on two sides of the effective area and a second edge area located on one side of the first edge area, and forming a fin portion on the substrate; forming a first graph layer covering an effective area fin portion and a first edge area fin portion; etching to remove a fin portion with a first thickness of the second edge area; forming a second graph layer covering the effective area fin portion; and taking the second graph layer as a mask layer, and etching to remove the fin portion with a second thickness of the first edge areas, wherein the second thickness is less than the first thickness. In the invention, through reducing an amount of the fin portion which is etched and removed on the substrate of the first edge areas next to the effective area, etching damages of the second graph layer are reduced or avoided so that the fin portion on the substrate of the effective area is prevented from exposing in an etching environment; the fin portion on the substrate of the effective area is prevented from being etched and damaged; and the fin portion on the substrate of the effective area possesses good morphology so that performance of the formed fin-type field-effect transistor is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for forming a fin field effect transistor. Background technique [0002] With the continuous development of semiconductor process technology, the development trend of semiconductor process nodes following Moore's Law continues to decrease. In order to adapt to the reduction of process nodes, the channel length of MOSFET field effect transistors has to be continuously shortened. The shortening of the channel length has the advantages of increasing the die density of the chip and increasing the switching speed of the MOSFET field effect tube. [0003] 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 that 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 pheno...

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Problems solved by technology

[0005] However, the performance of the fin field effect transistor formed by the prior art needs to be further improved

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