The present subject matter relates to systems, devices, and methods for reducing surface dielectric charging in a RF MEMS actuator element. In particular, a micro-electro-mechanical systems (MEMS) can comprise a fixed electrode positioned on a substrate, a moveable electrode positioned substantially above the fixed electrode and separated from the fixed electrode by a gap, and at least one standoff bump positioned between the fixed electrode and the moveable electrode, wherein the at least one standoff bump extends into the gap. In this configuration, one or both of the fixed electrode or the moveable electrode can be patterned to define one or more hole that is substantially aligned with the one or more of the at least one standoff bump. The bump and the hole can both help to reduce the rate of surface dielectric charging and the total amount of charge generated.

A MEMS switch contains an RF electrode 102, pull-down electrodes 104 and anchor electrodes 108 located on a substrate 101. A plurality of islands 226 are provided in the pull-down electrode and electrically isolated therefrom. On top of the RF electrode is the RF contact 206 to which the MEMS-bridge 212, 214 forms an ohmic contact in the pulled-down state. The pull-down electrodes 104 are covered with a dielectric layer 202 to avoid a short-circuit between the bridge and the pull-down electrode. Contact stoppers 224 are disposed on the dielectric layer 202 at locations corresponding to the islands 226, and the resulting gap between the bridge and the dielectric layer in the pulled-down state reduces dielectric charging. In alternative embodiments, the contact stoppers are provide within the dielectric layer 202 or disposed on the islands themselves and under the dielectric layer. The switch provides good controllability of the contact resistance of MEMS switches over a wide voltage operating range.

A microelectromechanical system (MEMS) switch with liquid dielectric and a method of fabrication thereof are provided. In the context of the MEMS switch, a MEMS switch is provided including a cantilevered source switch, a first actuation gate disposed parallel to the cantilevered source switch, a first drain disposed parallel to a movable end of the cantilevered source switch, and a liquid dielectric disposed within a housing of the microelectromechanical system switch.

Disclosed are systems and methods of operation for capacitive radio frequency micro-electromechanical switches, such as CMUT cells for use in an ultrasound system. An RFMEMS may include substrate, a first electrode connected to the substrate, a membrane and a second electrode connected to the membrane. In some examples, there is a dielectric stack between the first electrode and the second electrode and flexible membrane. The dielectric stack design minimizes drift in the membrane collapse voltage. In other examples, one of the electrodes is in the form of a ring, and a third electrode is provided to occupy the space in the center of the ring. Alternatively, the first and second electrodes are both in the form of a ring and there is a support between the electrodes inside the rings.

A MEMS switch contains an RF electrode 102, pull-down electrodes 104 and anchor electrodes 108 located on a substrate 101. A plurality of islands 226 are provided in the pull-down electrode and electrically isolated therefrom. On top of the RF electrode is the RF contact 206 to which the MEMS-bridge 212, 214 forms an ohmic contact in the pulled-down state. The pull-down electrodes 104 are covered with a dielectric layer 202 to avoid a short-circuit between the bridge and the pull-down electrode. Contact stoppers 224 are disposed on the dielectric layer 202 at locations corresponding to the islands 226, and the resulting gap between the bridge and the dielectric layer in the pulled-down state reduces dielectric charging. In alternative embodiments, the contact stoppers are provide within the dielectric layer 202 or disposed on the islands themselves and under the dielectric layer. The switch provides good controllability of the contact resistance of MEMS switches over a wide voltage operating range.

An approach includes a method of fabricating a switch. The approach includes forming a fixed electrode, forming a first cantilevered electrode, forming a second cantilevered electrode aligned vertically over the first fixed electrode, and which has an end that overlaps and is operable to directly contact an end of the first cantilevered electrode upon an application of a voltage to the fixed electrode, and forming a hermetically sealed volume encapsulating the first fixed electrode, the second fixed electrode, the first cantilevered electrode, and the second cantilevered electrode.

A microelectromechanical system (MEMS) switch with liquid dielectric and a method of fabrication thereof are provided. In the context of the MEMS switch, a MEMS switch is provided including a cantilevered source switch, a first actuation gate disposed parallel to the cantilevered source switch, a first drain disposed parallel to a movable end of the cantilevered source switch, and a liquid dielectric disposed within a housing of the microelectromechanical system switch.

An approach includes a method of fabricating a switch. The approach includes forming a first fixed electrode and a second fixed electrode, forming a first cantilevered electrode aligned vertically over the first fixed electrode, forming a second cantilevered electrode aligned vertically over the second fixed electrode, and which has an end that overlaps and is operable to directly contact an end of the first cantilevered electrode upon an application of a voltage to at least one of the first fixed electrode and the second fixed electrode, and forming a hermetically sealed volume encapsulating the first fixed electrode, the second fixed electrode, the first cantilevered electrode, and the second cantilevered electrode.

An approach includes a method of fabricating a switch. The approach includes forming a first fixed electrode and a second fixed electrode, forming a first cantilevered electrode aligned vertically over the first fixed electrode, forming a second cantilevered electrode aligned vertically over the first fixed electrode and which has an end that overlaps the first cantilevered electrode, forming a third cantilevered electrode aligned vertically over the second fixed electrode and operable to directly contact the first cantilevered electrode upon an application of a voltage to the second fixed electrode, and forming a hermetically sealed volume encapsulating the first fixed electrode, the second fixed electrode, the first cantilevered electrode, and the second cantilevered electrode.

An approach includes a method of fabricating a switch. The approach includes forming a first cantilevered electrode, forming a second cantilevered electrode over an electrode and operable to contact the first cantilevered electrode upon an application of a voltage to the electrode, and forming an arm on the first cantilevered electrode with an extending protrusion extending upward from an upper surface of the arm.