A Fluid Dynamic Study of a Microcontaminant Particles Removal Process

Abstract

Flow visualization techniques are used to study microcontaminant particles removal using drag and centrifugal forces (wafer rinsing). This removal process is an effective and commonly used method in the semiconductor industry. Understanding the flowfield around the rotating wafers is essential in determining the effectiveness and efficiency of the process. Flow visualization is used to observe the effect of rotational speed, jet flow rate and nozzle type on the flow pattern on the wafers. Optical and novel chemical flow visualization techniques are used. The qualitative and quantitative results show that the rotating wafers were completely covered with a water-film (that provides the drag force) only at certain values of the governing parameters. An empirical correlation between the water-film coverage and the operating parameters is introduced. A three-dimensional turbulent time-dependent prediction procedure for swirling flows is used to predict the flow around the wafers. Predictions of the trajectories of the water droplets issued from a peripheral jet into the flowfield between two rotating disks are also performed and the results presented.