Properties of amorphous SiO 2 films prepared by reactive RF magnetron sputtering method

Abstract

Amorphous SiO 2 (a-SiO 2) films were prepared by reactive RF magnetron sputtering method in an oxygen and argon mixture at room temperature. The chemical structure and electrical properties of the films were investigated as a function of the gas volume ratio [O 2]/[Ar]. When Ar was fixed at 40 sccm and O 2 was increased, deposition rate would decrease firstly, then increase and finally decrease. When the [O 2]/[Ar] ratio was larger than 0.075, oxide films having a stoichiometric composition can be obtained. With increasing [O 2]/[Ar], the resistivity and breakdown strength of electric field for the films increased, while buffered HF etch rate decreased. Neither absorption bands due to H–OH bonds in Fourier-transform spectra, nor porosity detected by electronic scan microscope was found in all films. It was suggested that the films were densified and had good dielectric properties.