Line Ratio of Optical Emission Spectroscopy Peaks for Predicting Deposition Rate and Refractive Index of Silicon Nitride in Plasma Enhanced Chemical Vapor Deposition Processes

Abstract

In this study, optical emission spectroscopy (OES) was used to predict the deposition rate and refractive index of silicon nitride (SiNx) deposited using trisilylamine (TSA), NH3 and N2 in plasma enhanced chemical vapor deposition (PECVD). The line ratio of (Formula presented.) strongly correlated with deposition rate (R2 = 0.85, MAPE = 3.66%). The line ratios of (Formula presented.) and (Formula presented.) correlated with refractive index, showing high accuracy (R2 = 0.95, MAPE = 0.27%). These ratios effectively predict deposition rate and refractive index by reflecting electron temperature and radical density variations.