Elementary Surface Reaction Simulation of Aluminum Chemical Vapor Deposition from Dimethylaluminumhydride Based on Ab Initio Calculations: Theoretical Process Optimization Procedure (2)

This work demonstrates how to develop a qualitative surface reaction model to an elementary surface reaction simulation of deposition for the quantitative examination of model validity. Chemical vapor deposition of Al (Al-CVD) from dimethylaluminumhydride (DMAH) is examined as an example of this method. The surface reaction model of DMAH was deduced from ab initio cluster model calculations and experimental measurements of reaction products. Rate constants of all the elementary reactions were estimated for an elementary reaction model. Transition-state theory enabled the calculation of rate constants using the activation energies obtained from ab initio calculations. Entropy terms, however, were estimated by using an empirical method to reduce the computational effort. This approach minimized the ab initio calculations required to form a reaction data set. Simulated deposition profiles were compared with experimental data for Al-CVD in a tube reactor. Good agreement between the results of simulations and experiments indicate the possibility of constructing surface-reaction data sets for CVD process simulations based on ab initio quantum-chemical calculations.