High Accuracy Simulation of Silicon Oxynitride Film Grown by Plasma Enhanced Chemical Vapor Deposition

摘要

Silicon oxynitride (SiOxNy) is a common barrier material in thin-film encapsulation (TFE) organic light-emitting diode (OLED). Substrate defects, voids and film internal defects occur during SiOxNy deposition process and result in poor film conformity and barrier failure. In this work, a mathematical model is built to evaluate experimental deposition rate and a high accuracy two dimensional model is proposed to predict the SiOxNy thin film profile evolution on arbitrary substrate in plasma enhanced chemical vapor deposition (PECVD) process. Based on level set method, image processing algorithm, iterative algorithm and velocity extension algorithm are proposed to ensure the high accuracy simulation. A series of design of experiments (DOEs) of SiOxNy film deposition are conducted to validate the model. For numerical deposition rate, the model predicted value fits the experimental data quite well and the offset in between has a root-mean-square error of 2.33. For film’s cross section profile, satisfactory agreement between model and scanning electron microscope (SEM) image is obtained, we use the step coverage as quantitative index for film uniformity, and the index’s prediction errors are all less than 4.