Kinetics Study on Initial Growth Stage in Vapor Deposition of Organic Thin Film Using Quartz Crystal Microbalance

Abstract

The deposition behavior of stearic acid evaporated in vacuum was observed using a quartz crystal microbalance technique, and the time evolution curves of the amount of admolecules in the initial growth were compared with a theoretical curve calculated using a rate equation proposed on the basis of physisorption. From the results, it was demonstrated that the proposed rate equation for the early stage of film formation well described the experimental results and the growth kinetics of organic thin films was dependent on the substrate temperature. Basic parameters for thin-film growth, such as the mean stay time on the substrate of deposited molecules, can be estimated from the fitting of the theoretical equation to the experimental results at each substrate temperature. It should be noted that the basic parameters were sensitive to a small change in substrate temperature.