Dry etching characteristics of titanium dioxide grown by different physical vapor deposition processes

The study of dry etching processes for titanium dioxide (TiO2) is of great significance for the fabrication of high-performance optical devices. TiO2 films were deposited in this work using both magnetron sputtering and electron beam evaporation methods. An inductively coupled plasma system was utilized to conduct dry etching of TiO2 to investigate the effects of various parameters on etching outcomes and explore the underlying etching mechanisms. Our findings reveal that bias power significantly influences the etching rate of TiO2. Moreover, appropriately increasing the bias power and chamber pressure can improve the surface roughness of the etched samples. Through optimization of process parameters, etching rates of 154.2 and 290 nm/min were achieved for magnetron-sputtered and electron beam-evaporated samples, respectively. The surface roughness was reduced to 0.51 and 0.78 nm, with sidewall angles reaching 83.5° and 84°.