Etching method

Abstract

The invention provides an etching method, which comprises the steps: providing a to-be-etched object, wherein the to-be-etched object comprises a substrate, a bottom anti-reflection coating covering the surface of the substrate, and a graphical photoresist layer disposed on a part of the surface of the bottom anti-reflection coating; and generating plasma under a preset gas source by taking the photoresist layer as a mask, performing plasma etching on the bottom anti-reflection coating, and removing the bottom anti-reflection coating, which is not covered by the photoresist layer, on the surface of the substrate, wherein in the etching process of the plasma on the bottom anti-reflection coating, the plasma formed by the gas source can form a polymer protection layer on the surface of the photoresist layer, and the part, not covered by the photoresist layer, of the bottom anti-reflection coating can be etched and removed. By applying the etching method provided by the embodiment of the invention, the selection ratio of the bottom anti-reflection coating to the photoresist layer is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to an etching method. Background technique [0002] Under the continuous promotion of Moore's Law, the technology node of semiconductor technology is rapidly advancing to the node below 10nm. At the same time, the development of the photoresist layer has also evolved from the wavelength band of 248nm to the wavelength band of 193nm. At present, the photoresist layer of extreme ultraviolet light (EUV) has been gradually promoted from 7nm. For the photoresist layer, as the exposure band decreases, the material of the photoresist layer is getting softer and softer. The film thickness is also getting thinner. Therefore, the selectivity ratio of the bottom anti-reflection coating to the photoresist layer is also higher and higher during the etching process. [0003] In the existing etching process, the selection ratio of the bottom anti-reflection coating to the ph...

AI Technical Summary

Problems solved by technology

In this way, the effective photoresist layer mask after etching is not enough, the effect of ion implantation becomes poor, and the area of ​​PN junction implantation will expand, thereby affecting the electrical properties and yield of semiconductor devices.

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