Abstract:
A MEMS structure that provides an improved way to selectively control electromechanical properties of a MEMS device with an applied voltage. The MEMS structure includes a capacitor element that comprises at least one stator element, and at least one rotor element suspended for motion parallel to a first direction in relation to the stator element. The stator element and the rotor element form at least one capacitor element, the capacitance of which varies according to displacement of the rotor element from an initial position. The stator element and the rotor element are mutually oriented such that in at least one range of displacements of the rotor element from an initial position, the second derivative of the capacitance with respect to the displacement has negative values.
Abstract:
Micromachined ultrasonic transducers integrated with complementary metal oxide semiconductor (CMOS) substrates are described, as well as methods of fabricating such devices. Fabrication may involve two separate wafer bonding steps. Wafer bonding may be used to fabricate sealed cavities in a substrate. Wafer bonding may also be used to bond the substrate to another substrate, such as a CMOS wafer. At least the second wafer bonding may be performed at a low temperature.
Abstract:
Micromachined ultrasonic transducers formed in complementary metal oxide semiconductor (CMOS) wafers are described, as are methods of fabricating such devices. A metallization layer of a CMOS wafer may be removed by sacrificial release to create a cavity of an ultrasonic transducer. Remaining layers may form a membrane of the ultrasonic transducer.
Abstract:
A method for manufacturing a capacitive transducer is provided having a structure in which a vibrating film (29) is supported to be able to vibrate. The method includes forming a sacrificial layer (25) on a first electrode (23); forming a layer on the sacrificial layer, the layer forming at least part of the vibrating film; removing the sacrificial layer, including forming etching holes (31) to communicate with the sacrificial layer; forming a sealing layer (33) for sealing the etching holes; and etching at least part of the sealing layer. Before forming the sealing layer, an etching stop layer (30) is formed on the layer forming at least part of the vibrating film. In the step of etching at least part of the sealing layer, the sealing layer is removed until the etching stop layer is reached.
Abstract:
A device with a suspended beam and piezoresistive means of detecting displacement of the beam and a method of manufacturing the device are disclosed. The device comprises a support, a suspended beam, moving parallel to the plane of the support, and means of detecting displacement, comprising at least two piezoresistive strain gauges that are not in line with each other. The beam is suspended through detection means. The two gauges are located on two opposite lateral faces of the beam respectively.
Abstract:
Provided is a microelectromechanical system (MEMS) that includes a first structure 100 and second structure 200. The first structure and second structure may each include a first substrate 110 and a second substrate 120. The first substrate of each structure may have first and second surfaces that face each other. The first substrate may include a via etching hole pattern penetrating the first surface and the second surface and a first non-via etching hole pattern penetrating the first surface. The second substrate 120 of each structure may have third and fourth surfaces that face each other. The second substrate may include a second non-via etching hole pattern penetrating the third surface in a position corresponding to the via etching hole pattern of the first substrate. In the microelectromechanical system (MEMS) the second surface of the first substrate and the third surface of the second substrate may be bonded together.
Abstract:
Microelectromechanical device comprising: a substrate (SS); a first layer (Ci) of a piezoelectric material, deposited on a surface of said substrate; a second layer (C2) of a semiconductor material, deposited on said first layer; at least one suspended element (ES), formed by extensions of said layers that extend beyond an edge (B) of said substrate; and a field-effect transistor (FET) integrated into said second layer and into its extension, having at least one channel that extends at least partly within said suspended element, comprising electrodes (D, S1, G) connected to conductive tracks (PCD) that extend on top of said second layer and at least one of which passes underneath said edge of the substrate; characterized in that at least two conductive tracks connected to two respective electrodes of the field-effect transistor overlap, without electric contact between them, so as to form a three-dimensional interconnection structure.