Resist distribution effect of spin coating

Abstract

The thin-film formation of the spin coating is one of the important factors in the fabrication of microelectronic devices. In this study, the theoretical models for thickness variation during spin coating and nanotopography impact are analyzed. The finite-difference–time-domain method and the finite-element method are used to solve the convective diffusion equation for solvent distribution and the Navier–Stokes equation including solvent evaporation for the film thickness change. These numerical calculations are in good agreement with experimental results for 193 nm chemically amplified resist (CAR) and i-line non-CAR resists. Solvent distributions of nonspin coating are described through mesoscale modeling by using the Monte Carlo method. Nanotopography impact on the variation of resist distribution after spin coating is investigated quantitatively. The reason for the similarity in the transfer functions for different types of wafers is due to solvent diffusion and evaporation.