Shang-Chou Chang, Shen Chi Hsieh, Kun Shan U., Taiwan; Tsung Chieh Cheng , Bau Tong Dai, National Nano Device Laboratories, Taiwan

OVERVIEW There is increasing interest in the thick, positive, epoxy-based photoresist made of the material AZ P4620 because of its wide applications in micro-fluidic devices and micro-electromechanical systems (MEMS). The optimization of polymerization for this material under near ultraviolet (UV) lithography was investigated and its mechanical and thermal properties were characterized. Optimal parameters for processing the AZ P4620 resist film were obtained for potential industrial usage.

MEMS technology is evolving at a rapid rate, with a wide variety of sensors and actuators becoming a reality. Currently, there is great interest in applying these technologies to fabricate fluid pumps [1-3]. For many MEMS processes, thick photoresists, such as AZ P4620 and SU-8, are suitable. Chen et al. [4] measured the contact angle and morphology of the oxygen plasma-treated SU-50 resist and found that the hydrophobic surface can be changed into a hydrophilic one by such a treatment. The mechanism was found to be the formation of a hydroxy band by a cross-link reaction in the initial polymerization….