Application of the LIGA process for fabrication of gas avalanche devices

Arrays of holes having steep wall sides have been successfully prepared by using a deep X-ray lithography technique, or LIGA process, on various thicknesses (50-1,000 /spl mu/m) polymethylmethacrylate (PMMA) plastic sheets. Electrical contact layers onto the top and bottom sides were deposited by metal evaporation in a vacuum. The completed LIGA devices were studied as an alternative design of the gas electron multiplier (GEM). The first measurements of performance were very promising: a lower limit to the avalanche gain of /spl sim/3,000 was obtained, and the actual gain is probably much larger. Detailed experimental results and field simulations will be described in this study. In addition, an application of a LIGA device to serve as a drift plane electrode, avoiding the angle dependency, is discussed.