A study on dry etching for profile and selectivity of ZrO2 thin films over Si by using high density plasma

In this study, we carried out an investigation of the etching characteristics (etch rate, selectivity to Si) of ZrO2 thin films in the HBr/SF6 high density plasma (HDP) system. The maximum etch rate of 54.8 nm/min for ZrO2 thin films was obtained at HBr(25%)/SF6(75%) gas mixing ratio. At the same time, the etch rate was measured as function of the etching parameters such as HDP source power, bias power, and chamber pressure. The X-ray photoelectron spectroscopy analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as showed an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the SF6-containing plasmas. (C) 2009 Elsevier B.V. All rights reserved.