The present invention is directed to assemblies configured using micro-electromechanical systems (MEMS) and micro-systems technology, and more particularly to improved micro-assemblies which have electrical capabilities.
The use of micro-hinges has become prevalent with the increased utilization and complexity of surface micro-machined components and systems. Typically used in the implementation of out-of-plane or vertically oriented micro-device designs, the micro-hinge is usually fabricated in a minimum two-layer, though typically three-layer, polysilicon process. Such a hinge, known as a staple hinge 10, is illustrated in FIG. 1 integrally connected with micro-mirror 12, and is used to attain out-of-plane motion. The multi-step fabrication process, includes depositing a layer which is then patterned and etched. Next a second layer is deposited, patterned and etched in such a way that after removing any filling material, the first layer is free to move in a prescribed path, while being held in place by the second layer. This structure creates a rotating joint implemented in MEMS or micro-systems to permit for the mechanical movement required for out-of-plane or vertically oriented devices.
While the described staple hinge provides a useful mechanical function, a drawback is the difficulty to incorporate electrical connections between the hinges and the micro-element to which it is attached. This difficulty is illustrated in FIG. 1, where it is shown that the lifted structure, i.e. micro-mirror 12 is floating above substrate 14. Providing an electrical connection between these physically separated elements raises significant obstacles to implementing a three-dimensional electrically actuated MEMs device such as an electrostatically driven micro-mirror. In order to realize scanning of a mirror, it is necessary for the mirror to be pushed and/or pulled mechanically by an actuator placed on substrate 14. Therefore it has been deemed desirable to develop micro-assemblies which are capable of providing an electrical connection between a hinge element and a micro-device, using a simplified structural arrangement.
Provided is a micro-electromechanical assembly including a micro-device formed in the device layer of a silicon-on-insulator substrate. A ribbon structure is formed in the same device layer, where the ribbon structure is less than the thickness of the micro-device. A connection interface provides a connection point between a first end of the micro-device and a first end of a ribbon structure, wherein the ribbon structure and micro-device are integrated as a single assembly. An electrical conductor is formed extending from one end of the ribbon structure to the micro-device tethered at the other end.