Analytical solutions of film planarization for periodic features

Analytical solutions of film profiles and degree of planarization for periodic features during the spin coating process are presented. This article shows that the degree of planarization is independent of Ω2 and changes slightly with the dimensionless line spacing α for Ω2>300. The governing dimensionless parameter Ω2 represents the ratio of centrifugal force to surface tension force during spin coating. In the cases of low Ω2 (Ω2<1), the degree of planarization decreases with increasing α for a fixed Ω2.