Method of forming semiconductor device

Abstract

The present invention provides a method for forming a semiconductor device, comprising: performing a first etching process, forming a second hard mask layer, a first hard mask layer, The first dielectric layer and the first groove of the composite nanosheet layer, the first groove extends into the substrate; a second dielectric layer is formed, and the second dielectric layer fills the first groove; removing The second hard mask layer to expose the first hard mask layer and the second dielectric layer higher than the first hard mask layer; forming a third hard mask layer, the third hard mask layer The mask layer covers the first hard mask layer and the top and sidewalls of the second dielectric layer; a self-aligned etching process is used to form through the adjacent regions of each N well region and P well region. The first hard mask layer, the first dielectric layer and the second groove of the composite nanosheet layer. A self-aligned etching process is adopted to reduce photolithography steps, reduce costs, and improve transistor performance.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for forming a semiconductor device. Background technique [0002] The Fin Field Effect Transistor (FinFET) architecture is the workhorse of today's semiconductor industry. However, as the device continues to shrink, when the channel length is small to a certain value, the fin field effect transistor structure cannot provide sufficient electrostatic control and sufficient driving current. Therefore, a nanosheet (Nanosheet) structure is introduced. Compared with fin field effect transistors, the characteristics of nanosheets provide excellent channel control capabilities, and at the same time, the excellent distribution of channels in three dimensions optimizes the effective drive current per unit area. [0003] As semiconductor device dimensions continue to shrink, further reductions in cell height will require smaller spacing between NMOS devices and...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a method for forming a semiconductor device to solve the problem of complex steps of fork-shaped nanosheet devices and the influence of critical dimensions and deviation changes on transistor characteristics

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