Substrate etching method

Abstract

Provided is a substrate etching method, comprising N times of substrate etching steps. In each time of substrate etching step, an etching gas is introduced into a reaction chamber, and an excitation power supply and a bias power supply are turned on to etch a substrate to a predetermined etching depth, where N is an integer greater than or equal to 2. It also comprises a plasma treatment step after the first time of substrate etching step and before the Nth time of substrate etching step. In the plasma treatment step, the introduction of the etching gas into the reaction chamber is stopped, simultaneously a treatment gas is introduced into the reaction chamber, and the bias power supply is turned off, the treatment gas being used for clearing away a part of reaction byproduct accumulated at the side wall of the substrate. The substrate etching method provided in the present invention not only can simplify the technological process, but also does not need to make any changes to an etching device on the premise of obtaining a substrate etching morphology with an ideal depth-to-width ratio, thereby being capable of reducing the manufacturing cost of devices.

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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