SUBMICRON LIGA PROCESS FOR MOVABLE MICROSTRUCTURES

The feasibility of making movable metal microstructures with lateral d imensions in the sub-micron range and aspect ratios of up to 100 was d emonstrated. These structures were manufactured by X-ray lithography i n resists approximately some ten micrometers high and with electroplat ed nickel. The small resist height, compared to deep X-ray lithography , allowed softer X-rays and lower absorbers on the mask to be used. Th erefore, no intermediate masks are needed and shorter beam times are p ossible. The small overall dimensions of devices with sub-micron dimen sions even with very high aspect ratios allow a much larger number of devices to be arranged on a wafer. This opens up a way to cost effecti ve manufacturing of movable microstructures on top of electronic circu its when the performance of the device is determined by the aspect rat io, not by its overall size.