Effect of water-contact on the roughness of patterned photoresist investigated by AFM analysis

Abstract

The effect of water-contact time on the roughness increment of patterned photoresist (AZ5214) was investigated by atomic force microscopy (AFM) analysis and the reason for the roughness increment was studied by the gravimetric experiment and the ellipsometry method. New method for calculating root-mean-square (RMS) line edge roughness from AFM data and the model of immersion lithography for experimentation were established. From the gravimetric experiments, it was confirmed that the diffusion of water into photoresist file is ruled my Fick's law. It was suggested that the amount of the roughness increment during rapid evaporation of water. As a result, the roughness of both the patterned line edge and the surface were proportioned in the root of water-contact time at the initial time and it was the same as the results in previous gravimetric experiments. (c) 2007 Wiley Periodicals, Inc.