A method for making a semiconductor device

Abstract

The present disclosure provides a method for making a semiconductor device. The method includes forming a material layer on a substrate; forming a sacrificial layer on the material layer, where the material layer and sacrificial layer each as a thickness less than 100 angstrom; forming a patterned photoresist layer on the sacrificial layer; applying a first wet etching process to etch the sacrificial layer to form a patterned sacrificial layer using the patterned photoresist layer as a mask; applying a second wet etching process to etch the first material layer; and applying a third wet etching process to remove the patterned sacrificial layer. The invention prolongs the etching time without photoresist peeling problem; or reduces the wet etching time of the second material layer to solve the photoresist peeling problem; or solves the problem that the photoresist is remained on the surface of the titanium nitride.

Description

technical field [0001] The invention relates to a method for manufacturing a semiconductor element, and in particular to a method for forming a sacrificial layer. Background technique [0002] With the progress of the technology node (node) of the integrated circuit industry, high dielectric constant materials (high k dielectric materials) and metals have been used to form metal-oxide-semiconductor field-effect transistors (MOSFETs) ) metal gate stack. In the method of forming a metal gate stack structure, a metal layer is deposited and etched. In the process of metal etching, the processing window is insufficient and the photoresist may peel off. In addition, the metal film exposed to the photoresist cannot be completely removed by etching, and the patterned photoresist peels off from the metal film it covers. Furthermore, the etching solution used in the wet etching process may penetrate into the interface between the patterned photoresist and the metal film, and oxidiz...

AI Technical Summary

Problems solved by technology

In the process of metal etching, the processing window is insufficient and the photoresist may be peeled off

In addition, the metal film exposed to the photoresist cannot be completely removed by etching, and the patterned photoresist will peel off from the metal film it covers

Furthermore, the etching solution used in the wet etching process may penetrate into the interface between the patterned photoresist and the metal film, and oxidize the metal film under the patterned photoresist, which will cause the metal film to deteriorate. and reduced component performance

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