Three-dimensional photoresist image simulation on flat surfaces

A simulation procedure for three-dimensional (3-D) photoresist images on flat substrates is developed. The procedure consists of three parts, i.e., two-dimensional (2-D) distribution of projected light intensity, 3-D photosensitizer concentration distribution, and 3-D photoresist development. For the former two simulations, conventional procedures have been employed. The last development simulation is carried out by extending the ray tracing model to three dimensions. A successful result is obtained for the resist system with a weak standing-wave effect.