Deposition Characteristics and Properties of SiO₂ Films Prepared by Reactive Sputtering in Hydrogen-, Oxygen- and Nitrogen-Argon Mixtures

Abstract

Films are deposited by reactive sputtering in hydrogen-, oxygen- and nitrogen-argon mixtures from an SiO 2 target in order to obtain device quality SiO 2 films at low temperature. Deposition characteristics and film properties of SiO 2 films sputtered in the mixtures are examined. Oxygen and nitrogen mixing with the sputtering gas leads to a large decrease in deposition rate compared with argon-only sputtering gas and hydrogen mixing. The SiO 2 film properties of the etching rate in BHF solution, surface morphology and resistivity are found to be greatly affected by mixing these gases with sputtering gas. Mixing of oxygen and a small amount of hydrogen provides excellent SiO 2 films, whose properties are superior to thermally grown films, even at low temperatures. These SiO 2 films have been used to successfully fabricate silicon electronic devices. The effects of mixing the reactive gases with the sputtering gas are also discussed qualitatively through plasma-surface interaction on growing film surfaces.