Numerical Simulation Study on Influence of Geometric Parameters of Spin-Coating Pallet on Wafer Deformation

Abstract

Spin-coating process is one of the important parts in the fabrication of semiconductor integrated circuits (IC). Numerical simulations and experiments based on Fluent were carried out, including discussing geometric parameters of spin-coating pallet that affect wafer deformation. The numerical results indicated that under the same effect of vacuum negative pressure, when wafer-supporting stage diameter (D) was smaller than 30mm, the wafer deformation was mainly warpage deformation; and when D was greater than 45mm, spin-coating pallet deformation affected the wafer deformation increasingly and downwarping deformation was occurred at the wafer edge. At the same exit velocity, the deformation around the wafer center and the vacuum degree were both increased with the increase of vacuum suction diameter (d). When the area of the wafer-supporting stage was 1/2~3/5 of the wafer and d was about 3mm, the wafer deformation was the smallest.