The proposed work will upgrade the Next-Generation Microshutter Array 3-electrode design to a 4-electrode design to reduce voltage requirements from a 100-150 V range to an anticipated 60 V to open up currently limited electrical hardware options and elevate shutter actuation reliability to maintain long lifetime shutter success rate of shutters on long-duration science missions. A new fabrication process using bonded silicon-on-insulator (BSOI) wafers will be developed to fabricate vertically separated wall sections that can be set to different voltages for efficient torque actuation. In parallel, a lap-and-regrow backside process will be explored to convert standard wafers with front side device fabrication completed into split-wall NGMSAs.

The current NGMSA design requires an operating voltage of 100-150 V range with relatively high current draw to generate instantaneous high torque for actuation of the shutters. This voltage level significantly raises the risk of shorts and increases the rate of dielectric degradation resulting in irrecoverable shutter failure. Moreover, a significant portion of the generated electrostatic force is not in the effective actuation direction. Large planar forces pull the shutter blade towards the surrounding walls, wasting electrical power, causing unreliable shutter motion, and increasing risk of stiction, rendering the pixel useless at best and causing light leakage and reduction in contrast in adjacent shutters at worst. To mitigate the risks, submicron fabrication requirements were implemented, thus increasing the time and cost it takes to produce a microshutter array. The split-wall design will increase the stability and robustness of microshutter control. The required voltage supply rate and magnitude will be reduced. And the electrostatic force profile on the microshutter will be effectively utilized for shutter motion. Increased yield and quality is expected with this new design and technique, making microshutters more available for high end as well as general science devices.

In addition, the BSOI wafer is an immerging industrial starting type wafer that warrants exploration for more complicated MEMS devices and will enhance our capability in producing detectors and tech devices with high level of capabilities.