Fabrication of gas amplification microstructures with SU8 photosensitive epoxy

Abstract

Recent advances in the field ofmicroelectromechanical systems (MEMS) research can be applied to the fabrication of gaseous electron-multiplying microstructures for use in imaging radiation sensors, and show interesting possibilities in addressing problems encountered with the gas micropattern generation ofradiation detectors in some applications, for example, gain instability and electrical breakdowns in high photon fluxes. The use ofSU8, an epoxy-based photoresist finding increasing use in MEMS and micromachining applications, is briefly discussed with regard to the construction of gas micropattern detectors, and several devices fabricated with the material are presented. Processes using the material can be adapted to a range ofdetector geometries, and the ability to fabricate higher level multilayer structures may also allow the incorporation ofadditional features such as guard electrodes to protect detectors and associated readout electronics against damaging spark events.