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.

The TaNO thin films were fabricated on standard 8 inch silicon wafers with a resistivity of 15 ~ 25 Ohm·cm. The TaNO thin film produced by the oxidation of deposited TaN films at 400℃ had a Vol. 18, No. 2, pp. 74-77, April 25, 2017 pISSN: 1229-7607 eISSN: 2092 Jong Chang Woo TRANSACTIONS ON ELECTRICAL AND ELECTRONIC MATERIALS Department of Electronic Automation Engineering, Daeduk University, Daejeon 34111, KoreaChang-Il Kim School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 06974, KoreaReceived September 20, 2016; Accepted November 22, 2016In this work, we investigated the etching characteristics of TaNO thin films and the selectivity of TaNO to SiO 2 in an O 2 /CF4/Ar inductively coupled plasma (ICP) system. The maximum etch rate of TaNO thin film was 297.1 nm/min at a gas mixing ratio of O 2 /CF 4 /Ar (6:16:4 sccm). At the same time, the etch rate was measured as a function of the etching parameters, such as the RF power, DC-bias voltage, and process pressure. X-ray photoelectron spectroscopy analysis showed the efficient destruction of the oxide bonds by the ion bombardment, as well as the 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 CF 4 -containing plasmas.

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