Substrate etching method

Abstract

The invention provides a substrate etching method. The substrate etching method comprises the following steps of etching a substrate, wherein etching gas is injected into a reaction chamber, an excitation power supply and a grid bias power supply are started to etch the substrate at preset etching depth; processing plasma, wherein the etching gas is stopped from being injected into the reaction chamber, meanwhile, processing gas is injected into the reaction chamber, the grid bias power supply is turned off, and the processing gas is used for removing a part of reaction by-products accumulated on the side wall of the substrate; the steps of etching the substrate is carried out cyclically for at least two times, and one time of the step of processing the plasma is carried out with at least one cyclical time in the total cyclical times in the step of etching the substrate as an interval. According to the substrate etching method, under the premise that substrate etched appearance with an ideal depth-to-width ratio is obtained, etching steps can be simplified, etching equipment does not need to be changed, and thus the manufacturing cost of the equipment can be lowered.

Description

technical field [0001] The invention relates to the technical field of microelectronics, in particular to a substrate etching method. Background technique [0002] In recent years, with the increase in the integration of semiconductor devices, the size of individual components has gradually become smaller, which has higher requirements for the etching process of etching shallow trenches on the substrate, in order to obtain ideal deep trenches. wide-ratio substrate etch topography. [0003] At present, people usually use a continuous etching method to etch the substrate, that is, the total etching depth of the substrate is etched in one step, and by adjusting the excitation power and the flow rate of etching gas (such as HeO) and other parameters to improve the smoothness of the sidewall topography of the substrate trench. However, when the substrate etching process is performed, especially when the process node is 32nm and below, the reaction by-products generated by the r...

AI Technical Summary

Problems solved by technology

[0011] First, due to the complicated etching steps of the above-mentioned substrate etching method, it is easy to cause contamination particles to fall during the entire substrate etching process, thereby causing the substrate to be contaminated, thereby reducing the yield of the product

[0012] Second, since the protective film formation process of the above-mentioned substrate etching method uses sputtering to form a protective film on the substrate, this method requires special design of the etching equipment so that it has a sputtering function, resulting in equipment increase in manufacturing costs

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