Numerical Study of Spin Coating Process Using the Thin Film Equation

Abstract

Spin coating technology is a method of uniformly coating a surface by rotating it and applying liquid material. This technology has found applications in various fields such as semiconductor manufacturing, optical component fabrication, medical device development, and the production of nano-bio sensors. It is commonly used in the photoresist coating during semiconductor manufacturing processes, contributing to the improvement of surface characteristics in optical components and enhancing the sensitivity of nano-biosensors. In the medical field, research is underway to enhance the antimicrobial properties and biocompatibility of medical device surfaces using spin coating technology. In various application areas, spin coating contributes to controlling the surface properties of materials and improving performance. Particularly in semiconductor manufacturing processes, achieving a uniform thin film is crucial, making spin coating an essential technology. However, the spin coating process involves several physical phenomena that are challenging to predict using numerical methods. In this study, a numerical approach based on the Thin Film Equation was employed to overcome these difficulties. The Thin Film Equation used in the research provides high accuracy at low computational costs, making it suitable for predicting the spin coating process under various conditions. The model calculates gravity, surface tension, contact angle, and centrifugal force to predict the liquid movement during the spin coating process. To validate the model used in the study, comparison and analysis were conducted against experimental results, confirming a good agreement. This allowed for identifying changes in semiconductor process recipes, such as optimal rotation speed and process time, based on variations in the liquid's viscosity coefficient during semiconductor photoresist spin coating processes.