Verification of the modified model of drying process of a polymer liquid film on a flat substrate by experiment

Abstract

We have proposed and modified a model of drying process of polymer solution coated on a flat substrate for flat polymer film fabrication and have presented the fruits through Photomask Japan 2002, 2003, 2004 and so on. And for example numerical simulation of the model qualitatively reappears a typical thickness profile of the polymer film formed after drying, that is, the profile that the edge of the film is thicker and just the region next to the edge’s bump is thinner. Then we have clarified dependence of distribution of polymer molecules on a flat substrate on a various parameters based on analysis of many numerical simulations. But above fruits are wholly based on theoretical and numerical studies and verification of the modified model by experiment has not sufficiently done yet except for one by the experiments of dependence of polymer molecule’s distribution on vaporization rate. In this paper, we verify the modified model by a few kinds of experiments. At first, we verify the dependence of polymer molecule’s distribution on intrinsic viscosity by experiment. In the concrete, we verify the characteristics that the smaller intrinsic viscosity is, the lower height of the edge’s bump is, the shallower depth of the valley next to the edge’s bump is and the more flat profile of polymer molecule’s distribution is at central region. Then we verify the dependence of polymer molecule’s distribution on the ratio of molar volume of solute to one of solvent by experiment.