A substrate etching method

Abstract

The invention discloses a substrate etching method and relates to the technical field of semiconductors. The substrate etching method includes: setting a multi-layer mask structure on the surface of the substrate, and forming a plurality of openings corresponding to the projection along the direction in which the substrate and the multi-layer mask structure are arranged on the multi-layer mask structure; The first pretreatment is performed on the corresponding partial surface to remove impurities on the partial surface; the partial surface that has undergone the first pretreatment is etched to form preset grooves corresponding to the plurality of openings on the substrate. The above method sets a multi-layer mask structure on the surface of the substrate, and etches the substrate with the multi-layer mask structure after forming a plurality of openings as a mask, so as to ensure that the openings on the multi-layer mask structure will not be damaged due to deformation. Affect the formation of the predetermined groove; at the same time, before etching the substrate, add a step to remove impurities on the surface of the substrate, so as to prevent the predetermined groove from being affected by the impurities on the surface of the substrate to cause micro-protrusion defects at the bottom of the predetermined groove.

Description

technical field [0001] The present invention relates to the technical field of semiconductors, in particular to a substrate etching method. Background technique [0002] The surface of the semiconductor device has an aluminum-containing material layer or a high-aluminum material layer. The aluminum-containing material layer or high-aluminum material layer usually contacts the oxygen in the environment to form impurities such as aluminum oxide. The hardness of impurities such as aluminum oxide is relatively high. It is difficult to remove when etching the trench, which will affect the morphology of the bottom of the trench. [0003] Due to the existence of impurities such as aluminum oxide, when the trench is directly etched by the commonly used plasma etching method, a columnar structure with a raised surface remaining due to incomplete etching will be formed at the bottom of the trench, and when it is necessary to etch When the width and depth of the etched groove are larg...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a substrate etching method to solve the technical problem in the prior art that when etching semiconductor devices, the groove shape error formed is relatively large

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