Etching characteristics of TaN thin film using an inductively coupled plasma

In this study, TaN thin films used as a diffusion barrier layer and electrode material were etched with an inductively coupled plasma. The TaN thin film was deposited on a SiO2 layer by ALD. The dry etching mechanism of the TaN thin film was studied as a function of the BCl3/N2 gas mixing ratio, RF power, DC-bias voltage and process pressure. When the gas mixing ratio was BCl3 (14 sccm)/N2 (6 sccm), with the other conditions fixed, the highest etch rate was obtained. As the RF power and DC-bias voltage were increased, the etch rate of the TaN thin film was increased. By decreasing the process pressure, the etch rate of the TaN thin film was also increased. The chemical reaction on the surface of the etched TaN thin film was investigated by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES).