2000 Volume 26 Issue 6 Pages 758-762
Chemical vapor deposition (CVD) films are widely used to make Very Large Scale Integrated Circuits (VLSIs). For optimum VLSI performance, precise control of both film thickness and composition is required. For this purpose, we carried out three-dimensional computer simulation of WSix CVD processes using WF6-SiH4 source gases in a cold-wall and single wafer type reactor. For this simulation we used the reaction model, the radical chain reaction model for CVD film formation developed by using analysis of the reaction kinetics from the results in the simplified reactor. By this simulation, agreement between simulated and measured values was approximately 5%. On the basis of this result, we investigated the effect of gas outlet number and outlet height position on the radial distribution of film deposition rate, composition and uniformity. When we selected the suitable outlet height position, the variation was improved remarkably less than 4%. This tendency might be explained by the gas velocity and gas composition distribution in the reactor. These results demonstrate how CFD simulations can be used to optimize CVD reactor design.