Dry Etching Properties of TiO₂Thin Film Using Inductively Coupled Plasma for Resistive Random Access Memory Application

In this work, we investigated to the etching characteristics of <TEX>TiO₂</TEX> thin film and the selectivity using the inductively coupled plasma system. The etch rate and the selectivity were obtained with various gas mixing ratios. The maximum etch rate of <TEX>TiO₂</TEX> thin film was 61.6 nm/min. The selectivity of <TEX>TiO₂</TEX> to TiN, and <TEX>TiO₂</TEX> to <TEX>SiO₂</TEX> were obtained as 2.13 and 1.39, respectively. The etching process conditions are 400 W for RF power, -150 V for DC-bias voltage, 2 Pa for the process pressure, and <TEX>40∘C</TEX> for substrate temperature. The chemical states of the etched surfaces were investigated with X-ray photoelectron spectroscopy (XPS). Its analysis showed that the etching mechanism was based on the physical and chemical pathways in the ion-assisted physical reaction.