Characteristics of Silicon Nitride Deposited Thin Films on IT Glass by RF Magnetron Sputtering Process

Abstract

Silicon nitride thin films are deposited by RF (13.57 MHz) magnetron sputtering process using a Si (99.999 %) target and with different ratios of Ar/N-2 sputtering gas mixture. Corning G type glass is used as substrate. The vacuum atmosphere, RF source power, deposit time and temperature of substrate of the sputtering process are maintained consistently at 2 similar to 3 x 10(-3) torr, 30 sccm, 100 watt, 20 min. and room temperature, respectively. Cross sectional views and surface morphology of the deposited thin films are observed by field emission scanning electron microscope, atomic force microscope and X-ray photoelectron spectroscopy. The hardness values are determined by nano-indentation measurement. The thickness of the deposited films is approximately within the range of 88 nm similar to 200 nm. As the amount of N-2 gas in the Ar:N-2 gas mixture increases, the thickness of the films decreases. AFM observation reveals that film deposited at high Ar:N-2 gas ratio and large amount of N2 gas has a very irregular surface morphology, even though it has a low RMS value. The hardness value of the deposited films made with ratio of Ar:N-2=9:1 display the highest value. The XPS spectrum indicates that the deposited film is assigned to non-stoichiometric silicon nitride and the transmittance of the glass with deposited SiO2-SixNy thin film is satisfactory at 97 %.