Abstract:
This disclosure provides systems, methods and apparatus for controlling a mechanical layer. In one aspect, an electromechanical systems device includes a substrate and a mechanical layer positioned over the substrate to define a gap. The mechanical layer is movable in the gap between an actuated position and a relaxed position, and includes a mirror layer, a cap layer, and a dielectric layer disposed between the mirror layer and the cap layer. The mechanical layer is configured to have a curvature in a direction away from the substrate when the mechanical layer is in the relaxed position. In some implementations, the mechanical layer can be formed to have a positive stress gradient directed toward the substrate that can direct the curvature of the mechanical layer upward when the sacrificial layer is removed.
Abstract:
In one embodiment, a method of forming a MEMS device includes providing a substrate, forming a sacrificial layer above the substrate layer, forming a silicon based working portion on the sacrificial layer, releasing the silicon based working portion from the sacrificial layer such that the working portion includes at least one exposed outer surface, forming a first layer of silicide forming metal on the at least one exposed outer surface of the silicon based working portion, and forming a first silicide layer with the first layer of silicide forming metal.
Abstract:
MEMS devices (40) using etched cavities (42) are desirably formed using multiple etching steps. Preliminary cavities (20) formed by locally anisotropic etching to nearly the final depth have irregular (46) sidewalls (44) and steep and/or inconsistent sidewall (44) to bottom (54) intersection angles (48). This leads to less than desired cavity diaphragm (26) burst strengths. Final cavities (42) with smooth sidewalls (50), smaller and consistent sidewall (50) to bottom (54) intersection angles (58), and having more than doubled cavity diaphragm (26) burst strengths are obtained by treating the preliminary cavities (20) with TMAH etchant, preferably relatively dilute TMAH etchant. In a preferred embodiment, a cleaning step is performed between the etching step and the TMAH treatment step to remove any anisotropic etching by-products present on the preliminary cavities' (20) initial sidewalls (44). The multi-step cavity etching procedure is especially useful for forming robust MEMS pressure sensors, but is applicable to any type of MEMS device.
Abstract:
A micromechanical structure and a method of fabricating a micromechanical structure are provided. The micromechanical structure comprises a silicon (Si) based substrate; a micromechanical element formed directly on the substrate; and an undercut formed underneath a released portion of the micromechanical element; wherein the undercut is in the form of a recess formed in the Si based substrate.
Abstract:
An apparatus comprising a microelectromechanical system. The microelectromechanical system includes a crystalline structural element having dislocations therein. For at least about 60 percent of adjacent pairs of the dislocations, direction vectors of the dislocations form acute angles of less than about 45 degrees.
Abstract:
A method of forming at least one Micro-Electro-Mechanical System (MEMS) includes forming a lower wiring layer on a substrate. The method further includes forming a plurality of discrete wires from the lower wiring layer. The method further includes forming an electrode beam over the plurality of discrete wires. The at least one of the forming of the electrode beam and the plurality of discrete wires are formed with a layout which minimizes hillocks and triple points in subsequent silicon deposition.
Abstract:
A method of forming a Micro-Electro-Mechanical System (MEMS) includes forming a lower electrode on a first insulator layer within a cavity of the MEMS. The method further includes forming an upper electrode over another insulator material on top of the lower electrode which is at least partially in contact with the lower electrode. The forming of the lower electrode and the upper electrode includes adjusting a metal volume of the lower electrode and the upper electrode to modify beam bending.
Abstract:
Methods of forming a protective coating on one or more surfaces of a microelectromechanical device are disclosed comprising the steps of forming a composite layer of a sacrificial material and a protective material, and selectively etching the sacrificial material to form a protective coating. The protective coatings of the invention preferably improve one or more aspects of the performance of the microelectromechanical devices in which they are incorporated. Also disclosed are microelectromechanical devices formed by methods of the invention, and visual display devices incorporating such devices.
Abstract:
Methods of forming a protective coating on one or more surfaces of a microelectromechanical device are disclosed comprising the steps of forming a composite layer of a sacrificial material and a protective material, and selectively etching the sacrificial material to form a protective coating. The protective coatings of the invention preferably improve one or more aspects of the performance of the microelectromechanical devices in which they are incorporated. Also disclosed are microelectromechanical devices formed by methods of the invention, and visual display devices incorporating such devices.
Abstract:
Electronic devices are disclosed that may be used for infrared radiation detection. An example electronic device includes a substrate, a transistor included in the substrate and a silicon-germanium (Si—Ge) structural layer coupled with the transistor. The structural layer has a stress in a predetermined range, where the predetermined range for the stress is selected prior to deposition of the structural layer. Also, the structural layer is deposited on the substrate subsequent to formation of the transistor such that deposition of the structural layer does not substantially adversely affect the operation of the transistor.