Substrate etching method

Abstract

The invention discloses a substrate etching method, and relates to the technical field of semiconductors. The substrate etching method comprises the following steps: arranging multiple layers of maskstructures on the surface of a substrate, and forming a plurality of openings corresponding to projections in the arrangement direction of the substrate and the multi-layer mask structure on the multiple layers of mask structures; carrying out first pretreatment on the local surface, corresponding to the plurality of openings, of the substrate to remove impurities on the local surface; and etchingthe local surface subjected to the first pretreatment so as to form preset grooves corresponding to the plurality of openings on the substrate. According to the method, the multiple layers of mask structures are arranged on the surface of the substrate, and the substrate is etched by taking the multiple layers of mask structures after the multiple openings are formed as masks, so that the openings in the multiple layers of mask structures are prevented from influencing the formation of the preset grooves due to deformation; meanwhile, before the substrate is etched, the step of removing impurities on the surface of the substrate is added, so that the defect that the bottom of the preset grooves slightly protrude due to the fact that the preset grooves are affected by the impurities on thesurface of the substrate is overcome.

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...

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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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