Applied Science and Convergence Technology 2024; 33(1): 27-31
Published online January 30, 2024
Copyright © The Korean Vacuum Society.
aDepartment of Control and Instrumentation Engineering, Korea University, Sejong 30019, Republic of Korea
bDepartment of Computer and Information Science, Korea University, Sejong 30019, Republic of Korea
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc-nd/4.0/) which permits non-commercial use, distribution and reproduction in any medium without alteration, provided that the original work is properly cited.
In this study, we evaluate the etch damage of silicon oxycarbide (SiOC) films in an inductively coupled plasma using a 2 MHz bias power frequency and compare it to the damage in a 13.56 MHz bias power system. For this study, CF4/He/Ar or CF4/C4F8/Ar mixed gas plasmas were used. To evaluate the plasma-exposed damage, ellipsometric spectroscopy (ellipsometry) and Fourier-transform infrared (FT-IR) spectroscopy were performed. The dielectric constant and Si-O/C-O area % ratios were extracted from ellipsometry and FT-IR results, respectively. We confirmed that ions among the plasma parameters, such as ions, ultraviolet, and radicals, have a significant impact on thin-film properties. Although the etching rate of the oxide film at 2 MHz was higher than that at a 13.56 MHz bias frequency, it was confirmed that the damage to the SiOC thin film at 2 MHz was lower than that at 13.56 MHz. In addition, FT-IR analysis proved to be a useful tool for evaluating the plasma damage in SiOC thin films. The polymer thickness was calculated through X-ray photoelectron spectroscopy. Based on these results, the effect of the polymer on the change in the Si-O/C-O ratio is discussed.
Keywords: Silicon oxycarbide, Dielectric constant, Fourier-transform infrared plasma etching damage, Surface characteristics