We found that a wet clean bath that has an interval chemical supply and a frequent flow change was quite effective for improving the cleaning performance under a constant value of total chemical supply amount. Using an interval chemical supply suggests a saving of chemical consumption which is environmentally friendly, and has a high throughput process. When wafers were placed with a wide spacing and a narrow spacing at the same time in the same wet clean bath, the particle removal efficiency was decreased noticeably at the narrow spacing compared to a wafer arrangement with equal spacing. In order to prevent the wet clean process from decreasing the cleaning performance, there must be a careful consideration of the wafer placement in the wet clean bath. Interestingly, a simulation of the supply flow velocity in a wet clean bath was correlated to experimental data of actual particle removability with various wafer spacing. We recognized that the wafer spacing and the chemical supply manner are important factors to controlling wet bath cleaning efficiency. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.012204jes] All rights reserved.