Resonantly enhanced addressing of a spatial light modulator micro-mirror array

A new addressing scheme is outlined for analog micro-mirror arrays where a resonant excitation enables maintained micro-mirror deflection with considerably reduced addressing voltage range. The resonant addressing supports enhanced writing performance in a spatial light modulator (SLM) based lithography system. The maximum deflection angle in the resonant deflection cycle, being in phase for all micro-mirrors, is made to coincide with the DUV exposure laser flash to enable printing of the required pattern. Substantially reduced addressing voltage can be achieved partly because of resonant enhancement of the deflection but also because of the possibility of reducing the mirror to electrode gap since the electrostatic pull-in effect is eliminated in the new addressing scheme. The removal of pull-in can be understood from the fact that the deflection at mechanical resonance frequency of the micro-mirrors is 90° out of phase with the oscillating exciting force.