Investigation of the Effect and Contribution of Process Parameters By Taguchi and ANOVA Analysis on the Morphological and Electrical Properties of RF Magnetron Sputtered SiO2 Over Si Substrate

In this work, we applied Taguchi Signal-to-noise (S/N) analysis to investigate the effect of varying three process parameters, namely — sputtering power, working pressure and Ar gas flow rate on the surface, morphological and electrical properties of the RF sputtered SiO2 over Si substrate. We also inspected the contribution of a particular process parameter on these properties by applying Analysis of Variance (ANOVA). SiO2 thin films were fabricated over Si substrate using RF magnetron sputtering system. Three sets of inputs for the three mentioned process parameters were chosen; for power, we chose 100W, 150W and 200W; 5mTorr, 10mTorr and 15mTorr were chosen for pressure and three Ar gas flow rate levels at 5, 10 and 15 sccm were selected. By performing Taguchi L9 orthogonal array, nine combinations of sputtering parameters were prepared for depositing SiO2/Si Thin films. The surface morphological and electrical properties (resistivity per unit area and capacitance per unit area) of the sputtered samples were therefore inspected by analyzing the Taguchi design of experiment. Signal-to-noise (S/R) analysis presents how the properties were affected by the variation of each process parameter. ANOVA analysis showed that sputtering power and working pressure are the two dominant process parameters contributing more to surface morphological and electrical properties. A regression model for surface roughness of the SiO2/Si thin film samples was also derived. The electrical properties of the SiO2/Si thin films, however, didn’t show linear properties.