Preparation and tunable optical properties of ion beam sputtered SiAlON thin films

One kind of quaternary thin films of SiAlON were deposited by ion beam sputtering method at ambient temperature, through a sintered SiAlON ceramic target. Ultraviolet, visible and near infrared (UV-VIS-NIR) Spectrophotometer, Fourier transformed infrared spectroscopy (FTIR), glancing incidence X-ray diffraction (GIXRD) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the optical, crystalline and chemical composition properties. The optical properties of the deposited amorphous films could be tailored by changing the relative content of O or N in the films, through introducing different working gas and gas flux adjusting (oxygen, nitrogen or their mixtures). By this way, the refractive index at 850 nm can be tailored from 1.53 to 1.83, and the chemical composition data from XPS analysis supplied strong evidences. Reasonably, the SiAlON films were thought to be one kind of candidate films either as a buffer layer benefit from their high temperature stability, or a mid infrared antireflective layer for silicon and other infrared window materials.