In this paper, we carried out the investigations of both etch characteristics and mechanisms for the SnO2 thin films in O2/BCl3/Ar plasma. The dry etching characteristics of the SnO2 thin films was studied by varying the O2/BCl3/Ar gas mixing ratio. We determined the optimized process conditions that were as follows: a RF power of 700 W, a DC-bias voltage of -150 V, and a process pressure of 2 Pa. The maximum etch rate was 509.9 nm/min in O2/BCl3/Ar=(3:4:16 sccm) plasma. From XPS analysis, the etch mechanism of the SnO2 thin films in the O2/BCl3/Ar plasma can be identified as the ion-assisted chemical reaction while the role of ion bombardment includes the destruction of the metal-oxide bonds as well as the cleaning of the etched surface form the reaction products.

We investigated the dry etching characteristics of TiN in TiN/A12O3: gate stack using a inductively coupled plasma system. TiN thin film is etched by BCI3/He plasma. The etching parameters are the gas mixing ratio, the RF power, the DC-bias voltages and process pressures. The highest etch rate is in BClilHe (25%:75%) plasma. The selectivity of TIN thin film to Al2O3 is pretty similar with BCI3/He plasma, The chemical reactions of the etched TiN thin films arc investigated by X - ray photoelectron spectroscopy, The intensities of the Ti 2p and the N is peaks are modified by BCl3: plasma, Intensity and binding energy of Ti and N could be changed due to a chemical reaction on the surface of TiN thin films. Also we investigated that the non volatile byproducts such as TiClx formed by chemical reaction with CI radicals on the surface of TiN thin films.

In this work, we investigated to the etching characteristics of the TiN thin film in He/BCl3/Cl2 plasma. The etch rate was measured by the gas mixing ratio, the RF power, the DC bias voltage and the process pressure. The maximum etch rate in He/BCl3/Cl2 plasma was 59 nm/min. The etch rate increased as the RF power and the DC-bias voltage was increased. The chemical reaction on the surface of the etched the TiN thin films was investigated with X-ray photoelectron spectroscopy (XPS). The intensity of Ti 2p and N 1s peaks are varied during etching process. A new peak was appeared in He/BCl3/Cl2 plasma. The new peak was revealed Ti-Clx by Cl 2p peak of XPS wild scan spectra analysis.

The etching characteristics of indium tin oxide (ITO) thin films in an O2/BCl3/Ar plasma were investigated. The etch rate of ITO thin films increased with increasing O2 content from 0 to 2 sccm in BCl3/Ar plasma, whereas that of ITO decreased with increasing O2 content from 2 sccm to 6 sccm in BCl3/Ar plasma. The maximum etch rate of 65.9 nm/m in for the ITO thin films was obtained at 2 sccm O2 addition. The etch conditions were the RF power of 500 W, the bias power of 200 W, the process pressure of 15 mTorr, and the substrate temperature of 40℃. The analysis of x-ray photo electron spectroscopy (XPS) was carried out to investigate the chemical reactions between the surfaces of ITO thin films and etch species.