Physical model of optical constants of SiO₂ thin films

SiO₂ thin films were deposited by ion beam sputtering (IBS) and electron beam evaporation (EB) technologies. The optical constants of SiO₂ thin films were fitted by nonlinear least square algorithm. 8 group experiments were designed based on L₈ (2²) orthogonal array. The results show that intermix is the most important factor for the IBS SiO₂ thin film while Proe model for the EB SiO₂ thin film. The values of MSE evaluation function for IBS SiO₂ thin film and EB SiO₂ thin film decline 35% and 38% respectively, which shows that the physical models are reasonable and the physical meaning is clear. The method to estimate the effect of different factors was offered, which is meaningful for the analysis of optical constants of thin films.