Spincoating Deposition of Thickness Gradient Polymer Films

Thickness gradient polymer films can be prepared by dropping one drop of a polymer solution onto a spinning substrate at a position that is displaced from the axis of rotation. In these films, the thickness increases with increasing radial distance. To understand the deposition process for thickness gradient films in more detail, we have measured the intensity of laser light reflected from thickness gradient films during spincoating deposition. The results obtained at different radial distances will be discussed and compared with those obtained for polymer films of uniform thickness.