Plasma processing device and adjustment method for improving etching symmetry

Abstract

The invention discloses a plasma processing device for improving etching symmetry. The device comprises a plasma reaction cavity, wherein a base is arranged at the bottom of the plasma reaction cavity and is used for placing a wafer, a limitation ring is arranged between the base and an inner wall of the plasma reaction cavity, a grounding ring is arranged under the limitation ring and is in radio frequency coupling to the limitation ring, and a spacing part is arranged between the grounding ring and the limitation ring and forms a spacing distance between the whole limitation ring and the grounding ring. The spacing part is arranged between the limitation ring and the grounding ring, thus, the spacing distance between the limitation ring and the grounding ring is expanded, great influence of slight disturbance of the size of a gap between the limitation ring and the grounding ring on a contact capacitor is prevented, the stability of the contact capacitor between the limitation ring and the grounding ring is improved, and the etching symmetry is improved.

Description

technical field [0001] The invention relates to a plasma etching technology, in particular to a plasma processing device and an adjustment method for improving etching symmetry. Background technique [0002] The Chinese application with publication number CN101568996A discloses a method and device for controlling airflow conduction in a capacitively coupled plasma processing chamber. The device includes: a bypass blocking ring; There is a first set of slots formed therein; a cover ring disposed on the base ring and the bypass blocker ring, the cover ring including a second set of slots formed therein. The bypass blocking ring controls the opening and closing of the first and second sets of slots, and controls the flow of gas in the first or second set of slots. This patent discloses that an annular mechanism is arranged in the processing chamber, but this mechanism cannot improve the problem of etching asymmetry. [0003] The U.S. application with the publication number US...

AI Technical Summary

Problems solved by technology

This patent discloses that the plasma is excited by the reactive gas to etch the wafer, but it does not disclose how to solve the problem of asymmetry in the plasma etching process

[0006] There are many factors that may cause etching asymmetry in the prior art, such as the gate for transferring wafers set on the side wall of the chamber, the asymmetric distribution of various joints in the lower chamber, and the gap between the confinement ring and the grounding ring. The size of the gap, etc., and even some unknown changes in the capacitance of the contact surface will have a great impact on the symmetry of the etching rate of some processes, which may lead to asymmetrical etching results

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