Optimization and application of Epon SU-8, an ultra-thick negative photoresist.
Tan, Khee Lip.
Date of Issue2000
School of Mechanical and Aerospace Engineering
Another application that requires ultra-thick photoresist films is micromachining in MEMS. Extremely large structure heights are frequently required for micro-electrodeposition of mechanical components such as coils, cantilevers and valves. These applications may require photoresist in excess of a hundred microns in thickness. The patterning of high aspect ratio structures in these ultra-thick photoresist films is extremely challenging. The aspect ratios easily exceed those encountered in submicron lithography for standard integrated circuit (IC) manufacturing. Unlike thin photoresist for IC manufacturing, lithography modelling and characterisation are not readily available for ultra-thick photoresist films.
Nanyang Technological University