Accurate particle selection is possible by using precisely patterned holes in a metal membrane. Metal filters are well suited for being used with organic chemicals and at high temperature.
Laser projection marking
Laser marking and trimming use micromachined masks for projecting the laser radiation through a reduction optics. If details below 10 micron are to be reproduced in the marking, a precision patterned mask is required. Such mask should preferably lay on no substrate, since this could be damaged by the laser radiation (typically high energy pulses from a Neodimium-YAG or an Excimer laser). A self sustaining electroformed mask can easily do the job.
Radiation broadband attenuation
Neutral density filters, with really broad and flat band, can be fabricated for non imaging applications. The transmission depends on the empty/full ratio in the metal layer. Variable transmission devices can be obtained by cascading two attenuators and rotating one with respect to the other. A typical attenuator for radiation measurement exhibits a flat response from deep UV to far IR, through VIS and near-IR. One such attenuator is shown in the first photograph below, where an integrated circuit is observed partly directly and partly through the filter (10% transmission). The next photograph shows the filters in reflected light. The last two SEM photographs show details of the filters.