Substrate etching method

Abstract

The invention provides a substrate etching method. The method comprises the steps that S1) etching gas, passivation gas and auxiliary gas are input into a reaction chamber, an excitation power supply and a bias power supply are started, and the inclination of an opening at the top of a groove is reduced by increasing the pressure of the chamber and the flow of the passivation gas and reducing the flow of the etching gas and the bias power of the bias power supply; and S2) after a preset technical time, the inclination of the middle and bottom portions of the sidewall of the groove is increased by reducing the pressure of the chamber and increasing the flow of the etching gas and the passivation gas. The etching gas comprises fluorine and sulfur composite gas, the passivation gas includes oxygen, and the auxiliary gas comprises inert gas. According to the substrate etching method, an ideal substrate appearance that the opening at the top of the groove inclines to form a V shape, the middle and bottom portions of the sidewall are steep, and the bottom surface is smooth can be obtained.

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 MEMS devices and systems being more and more widely used in the fields of automobiles and consumer electronics, and the broad prospects of TSV (Through Silicon Etch, through hole etching) in the future packaging field, deep silicon etching technology has gradually become One of the hottest processes in the field of MEMS processing and TSV technology. Moreover, for different applications, there are different requirements for the substrate morphology obtained by the deep silicon etching process. Requirements, and in order to ensure the performance and stability of the device, it is required that the top opening of the trench is inclined to be V-shaped, the middle and bottom of the side wall are steep, and the bottom surface is smooth, such as figure 1 shown. [0003] An existing substrate et...

AI Technical Summary

Problems solved by technology

like figure 2 As shown, the inclination angle of the top opening of the trench is too large, and as the process time increases, the critical dimensions at the bottom of the sidewall shrink severely, which will lead to etching interruption

As a result, the process cannot be carried out normally

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