Automatic process design for 3D thick-film grayscale photolithography

A novel process optimization tool for grayscale lithography is developed and demonstrated to fabricate three-dimensional (3D) microstructures using thick-film photoresists. For the first time, the two process parameters in grayscale lithography: exposure dose profile and development time are determined automatically for a user-specified target 3D profile. This provides an inexpensive and effective alternative to conventional trial-and-error based process design. The optimized parameters were verified by fabricating various 3D microstructures and the experiments revealed good quantitative agreement with the target profile.