Dry etching characteristics of HfAlO3 thin films in BCl3/Ar plasma using inductively coupled plasma system

In this study, we monitored the HfAlO3 etch rate and selectivity to SiO2 as a function of the etch parameters (gas mixing ratio, RF power, DC-bias voltage, and process pressure). A maximum etch rate of 52.6 nm/min was achieved in the 30% BCl3/(BCl3 + Ar) plasma. The etch selectivity of HfAlO3 to SiO2 reached 1.4. As the RF power and the DC-bias voltage increased, the etch rate of the HfAlO3 thin film increased. As the process pressure decreased, the etch rate of the HfAlO3 thin films increased. The chemical state of the etched surfaces was investigated by X-ray Photoelectron Spectroscopy (XPS). According to the results, the etching of HfAlO3 thin films follows the ion-assisted chemical etching mechanism. (C) 2011 Elsevier Ltd. All rights reserved.