• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.146-151
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• 2011

Wax spin coating is a part of several wafer handling processes in the silicon wafer polishing station. It is important to ensure the wax layer free of contamination to achieve the high degree of planarization on wafers after wafer polishing. Three-dimensional air flow characteristics in a wax spin coater are numerically investigated using computational fluid dynamics techniques. When the bottom of the wax spin coater is closed, there exists a significant recirculation zone over the rotating ceramic block. This recirculation zone can be the source of wax layer contamination at any rotational speed and should be avoided to maintain high wafer polishing quality. Thus, four air suction ducts are installed at the bottom of the wax spin coater in order to control the air flow pattern over the ceramic block. Present computational results show that the air suction from the bottom is quite an effective method to remove or minimize the recirculation zone over the ceramic block and the wax coating layer.

• Journal of the Semiconductor & Display Technology
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• v.10 no.1
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• pp.1-6
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• 2011

In this paper, the air flow induced by the rotating flat disk is numerically investigated in a hope to better understand the air flow structures inside the wax spin coater for a silicon wafer polishing station. Due to the complex inner geometry of actual spin coater such as the casing around the rotating ceramic block and servo motor, recirculation of air flow is inevitably found on the coating target if the internal space of spin coater is closed at the bottom and it could be the possible source of contamination on the wax coating. By numerical flow simulation, we found that it is necessary to install the air vent at the bottom and to apply the sufficient air suction in order to control the path of air flow and to eliminate the air recirculation zone above the spinning surface of coating target.