Modeling and simulations of SU-8 UV lithography using a novel 3-D string algorithm

This paper presents a three-dimensional (3-D) string algorithm and its application to SU-8 UV lithography simulations. 2-D normal vectors are used to be components of a 3-D normal vector, so as to get the evolvement direction of certain surface node in 3-D space. After the diffraction, absorption rate changing with depth, and cross-linking effect are combined, an improved model of SU-8 UV lithography process is developed based on the 3-D string algorithm. This model can describe the surface evolution process effectively, and the simulated result keeps accordance with the experiment. It provides the possibility of this 3-D algorithm being used to predict the fabrication profiles of micromachining in practice.