CFD Analysis of flow structure between rotating disks for semiconductor photoresist stripping using high concentrated ozone water

In the photoresist stripping process of semiconductor manufacturing, the cleaning method with the ozone water and a disk-shaped nozzle is proposed in authors' previous studies. Moreover, it is suggested that the three-dimensional flow structure of the ozone water between a rotating silicon wafer and the disk-shaped nozzle affects photoresist stripping rate. The purpose of the present study is to reveal this flow structure. In order to reveal this flow structure, the visualization experiment with dye, stereoscopic micro-PTV measurement and CFD analysis are conducted. As a result, the injected dye forms contrasting density, and a high concentrated area is indicated near the disk end. On the other hand, CFD analysis is conducted with 5 models ; laminar model, k-e model, Lam-Bremhorst k-e model (1981), Launder-Sharma k-e model (1974) and Lien-Leschziner k-e model (1999). The result suggests that Lien-Leschziner k-e is the most appropriate model for the present study. It is cleared that there is a transition radius of flow structure. It is suggested that the transition radius also depends on the balance between the inertial force and the force caused by the adverse pressure gradient. Furthermore, the photoresist stripping rate increases where the wall shear stress is strong. As a result, it is suggested that the wall shear stress affects the rate of photoresist stripping. © 2013 The Japan Society of Mechanical Engineers.