Fabrication of electrostatically actuated silicon nitride microshutter arrays

We have developed a new back side fabrication process to actuate microshutter arrays (MSA) electrostatically at the NASA Goddard Space Flight Center. The microshutters are fabricated on silicon with thin silicon nitride membranes. The microshutters rotate 90° on torsion bars. The selected microshutters are actuated, held, and addressed electrostatically by applying voltages on the electrodes the front and back sides of the microshutters. The atomic layer deposition (ALD) of aluminum oxide (AhO3) was used to insulate electrodes on the back side of walls; the insulation can withstand over 100 V. The ALD aluminum oxide is dry etched, and then the microshutters are released in vapor HF. A monolayer of perfluorodecyltrichlorosilane (FDTS) was deposited to prevent stiction.