The thin film deposition property and the process difference during the wafer size migration from 12 '' (300 mm) to 18 '' (450 mm) in the Chemical Vapor Deposition (CVD) equipment is improved and reduced, respectively, when the chamber hardware is designed with the help of 3D full chamber modeling and 3D experimental visual technique developed in this work. The accuracy of 3D chamber simulation model is demonstrated with the experimental visual technique measurement. With the CVD chamber hardware design of placing the inlet position and optimizing the distance between the susceptor edge and the reactor wall, the better thin film deposition property and the larger process compatibility during the wafer size migration from 12 '' (300 mm) to 18 '' (450 mm) for the industry cost reduction can be achieved. Non-dimensional Nusselt parameter is also found to be the effective indicator to monitor the thin film deposition property. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.