Method for fabricating semiconductor device

Abstract

A method for fabricating a semiconductor device comprises the following steps. A substrate having a first area and a second area is provided. The substrate is patterned to form trenches in the substrate and semiconductor fins between the trenches, wherein the semiconductor fins comprises first semiconductor fins distributed in the first area and second semiconductor fins distributed in the second area. A first fin cut process is performed in the first area to remove portions of the first semiconductor fins. Insulators are formed in the trenches after the first fin cut process is performed. A second fin cut process is performed in the second area to remove portions of the second semiconductor fins until concaves are formed between the insulators in the second area. A gate stack is formed to partially cover the first semiconductor fins, the second semiconductor fins and the insulators.

Description

technical field [0001] Embodiments of the invention relate to a method of fabricating a semiconductor device. Background technique [0002] As the size of semiconductor devices continues to shrink, three-dimensional multi-gate structures (such as fin-type field effect transistors (FinFETs)) have been developed to replace planar CMOS (Complementary Metal Oxide Semiconductor, CMOS) device. The structural feature of the fin field effect transistor is a silicon-based fin (silicon-based fin) extending upright from the surface of the substrate, and the gate wrapped around the conduction channel formed by the semiconductor fin further provides a more accurate view of the channel. Good electrical control. [0003] During the fabrication of FinFETs, semiconductor fins are patterned by a fin cut last process to remove unwanted portions of the semiconductor fins, and after the fin cut process, shallow trenches are then formed Isolation (shallow trench isolation, STI) and gate stack ...

AI Technical Summary

Problems solved by technology

Since the patterned photoresist layer used in the fin cutting process is formed over the substrate, and thus the patterned photoresist layer may not be thick enough to protect the covered semiconductor fins, especially in densely populated areas of the semiconductor device ( For example, semiconductor fins in the core area), therefore, fin damage occurs during the fin cutting process and the stability of the fin cutting process deteriorates

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