The dry etching property of TiO2 thin films using metal-insulator-metal capacitor in inductively coupled plasma system

In this work, we investigated the etching characteristics of TiO2 thin films and the selectivity of TiO2 to SiO2 in a BCl3/Ar inductively coupled plasma (ICP) system. The maximum etch rate of 84.68 nm/min was obtained for TiO2 thin films at a gas mixture ratio of BCl3/Ar (25:75%). In addition, etch rates were measured as a function of etching parameters, such as the RF power, DC-bias voltage and process pressure. Using the X-ray photoelectron spectroscopy analysis the accumulation of chemical reaction on the etched surface was investigated. Based on these data, the ion-assisted physical sputtering was proposed as the main etch mechanism for the BCl3-containing plasmas.

► The etching characteristics of TiO2 thin film were investigated by the etch parameters in an ICP.
► The characteristics of the plasma were estimated using OES.
► The TiO2 thin films follow the ion assisted chemical etching mechanism.