Submicron, movable gallium arsenide mechanical structures and actuators

Movable, complex single-crystal gallium arsenide (SC-GaAs) structures with up to a 25:1 aspect ratio of vertical depth (10 μm) to lateral width (400 nm) were fabricated. A process called SCREAM II (for single crystal reactive etching and metallization) was used to fabricate the submicron, SC-GaAs electromechanical structures. SC-GaAs anisotropic and isotropic dry etches were used to form the movable SC-GaAs mechanical structures etched from an SC-GaAs substrate using a PECVD-SiN_x:H or PECVD-SiO_x:H mask to protect the top and the sidewalls of the SC-GaAs structures. An integrated sidewall metallization process was used to deposit aluminum on deep vertical sidewalls to fabricate the capacitor actuators. The fabrication process was used to produce complex, submicron, SC-GaAs electromechanical structures. An x-y stage with integrated, high-aspect-ratio capacitor actuators was fabricated using this process. A maximum x-y motion of ±6 μm was achieved with x-y actuator voltage of 65 V