Spin coating is a widely spread method to form a thin film on the flat disk. The effect of temperature-dependent viscosity of coating fluid is studied by predicting film thickness and analyzing stability of a steady axisymmetric viscous flow.
The steady axisymmetric flow and temperature fields are obtained numerically when the temperature of free surface is assumed to be higher than that of disk. The larger temperature difference ΔT between free surface and disk, the better film uniformity.
Temporal development of infinitesimal travelling wave is examined by linear stability analysis. Time exponents of disturbance are obtained numerically as eigenvalues of linear system under given axial(α) and azimuthal(n) wave numbers. The results show that the larger ΔT, the more unstable spin coating flow.
