Abstract
By optical lithography, a wave shape is formed on a side-wall of a column type resist pattern due to standing wave effect which occurs during exposure process. After the pattern collapse with atomic force microscope (AFM), surface topography of the pattern side-wall can be imaged clearly. Based on standing wave effect, refractive index distribution of the resist pattern can be estimated to be the range from 1.51 to 1.79. It is clarified that refractive index at the pattern bottom is relatively high comparing with that of the pattern top. This tendency reflects the distribution of cohesion strength of the resist pattern resulting from the heat treatment with a hot plate. By this method, optical and cohesion properties of a micro condensed matter can be analyzed quantitatively.
