Modelling of Cu thin film growth by MOCVD process in a vertical reactor

Abstract

Transport phenomena in a vertical reactor for metalorganic chemical vapor deposition (MOCVD) of copper thin films have been analyzed by numerical simulation of the process. The equations of the mathematical model were solved numerically using the Galerkin finite element method, Newton-Raphson iterations and the frontal algorithm for the gas flow structure, temperature distribution and concentration distribution of the reacting species. Deposition rates of copper thin films using Cu(hfac)VTMS as a precursor were estimated from numerical solutions. Standard process conditions were selected as: a reactor pressure of 1 Torr, a substrate temperature and inlet gas temperature of 200 degrees C and 70 degrees C, respectively, and an inlet gas flow rate of 50 sccm. Under standard conditions, the deposition rates of copper were in the range of 160-230 Angstrom/min. The effects of the process conditions, reactor geometry and shower head structure on the deposition rate and thickness uniformity were examined. It has been demonstrated that numerical simulation can be used for improving the film thickness uniformity and the utilization of source gas.