Plasma treatment method and plasma treatment device

Abstract

According to the present invention, a desired shape is etched by means of highly-precise control and long-term stabilization of the thickness of a film that is deposited on a pattern during cyclical etching that proceeds by the repetition of a deposition step and an etching step. The present invention comprises: a deposition step (S1) for introducing a reactive, depositing gas into a treatment chamber to form a deposit layer on the surface of an etching pattern of an etching substrate; an etching step (S2) for removing the product of a reaction between the deposit layer and the surface of theetching pattern; and a step (S3) for shining light onto the etching pattern during the deposition steps that form the deposit layer during cyclical etching in which the deposition step and the etchingstep are alternatingly executed to produce a fine pattern and monitoring the change in the film thickness of the deposit layer on the basis of the change in interference light of a specific wavelength that has been reflected by the etching pattern. Treatment conditions for the steps that will form the deposit layer during subsequent cycles of the cyclical etching are determined such that a deposited film thickness index that is calculated from the monitored change in the film thickness of the deposit layer falls within a prescribed range in comparison with reference data.

Description

technical field [0001] The present invention relates to a plasma processing method and a plasma processing device, and particularly to a plasma etching technique suitable for controlling the thickness of a deposited film on a pattern. Background technique [0002] Due to the miniaturization of functional device products such as semiconductor devices, the development of device processing technologies using multiple patterning such as double patterning using the side walls of the partition walls of thin films as masks is accelerating. [0003] Along with this, in the process of processing devices such as three-dimensional devices, the technology of trench processing using various insulating materials such as film partition walls as a mask has become important. Thicknesses of masks, gate insulating films, etching stoppers, etc. are reduced, and highly selective processing that controls shapes at the atomic layer level is required. In addition, with the three-dimensionalization...

AI Technical Summary

Problems solved by technology

However, in such cyclic etching using a gas with high accumulation property, it is necessary to precisely control etching parameters such as the amount of deposition in the deposition process and the ion energy in the etching process to perform etching. The atmosphere changes with time, etc., it is difficult to control the deposition process and etching process stably for a long time to etch into the desired shape

Images