A method and apparatus are for controlling stress variation in a material layer formed via pulsed DC physical vapour deposition. The method includes the steps of providing a chamber having a target from which the material layer is formed and a substrate upon which the material layer is formable, and subsequently introducing a gas within the chamber. The method further includes generating a plasma within the chamber and applying a first magnetic field proximate the target to substantially localise the plasma adjacent the target. An RF bias is applied to the substrate to attract gas ions from the plasma toward the substrate and a second magnetic field is applied proximate the substrate to steer gas ions from the plasma to selective regions upon the material layer formed on the substrate.

A diaphragm for use in a transducer, the diaphragm including a flexible layer configured to deflect in response to changes in a differential pressure. The flexible layer includes a lattice grid. The lattice grid includes a first plurality of substantially elongate openings oriented along an axis and a second plurality of substantially elongate openings extending generally parallel to the axis. The second plurality of openings is substantially offset from the first plurality of openings in a direction substantially parallel to the axis. The first plurality of openings and the second plurality of openings define a first plurality of spaced apart grid beams extending between and substantially parallel to the axis and a second plurality of spaced apart grid beams extending substantially perpendicular to the axis. The second plurality of grid beams is configured to connect adjacent ones of the first plurality of grid beams.

A piezoelectric microelectromechanical systems device is provided, having a first piezoelectric layer, a first metal layer including a first metal, a second metal layer including a second metal, the first and second metals having different properties to compensate deflection due to thermal stress of any or all of the piezoelectric layer, the first metal layer, and second metal layer and a substrate including at least one wall defining a cavity and the at least one wall supporting the layers. The method for making the piezoelectric microelectromechanical systems device is also provided.

A described example includes: a MEMS component on a device side surface of a first semiconductor substrate; a second semiconductor substrate bonded to the device side surface of the first semiconductor substrate by a first seal patterned to form sidewalls that surround the MEMS component; a third semiconductor substrate having a second seal extending from a surface and bonded to the backside surface of the first semiconductor substrate by the second seal, the second seal forming sidewalls of a gap beneath the MEMS component. A trench extends through the first semiconductor substrate and at least partially surrounds the MEMS component. The third semiconductor substrate is mounted on a package substrate. A bond wire or ribbon bond couples the bond pad to a conductive lead on the package substrate; and mold compound covers the MEMS component, the bond wire, and a portion of the package substrate.

Described herein is a ruggedized microelectromechanical (“MEMS”) force sensor including both piezoresistive and piezoelectric sensing elements and integrated with complementary metal-oxide-semiconductor (“CMOS”) circuitry on the same chip. The sensor employs piezoresistive strain gauges for static force and piezoelectric strain gauges for dynamic changes in force. Both piezoresistive and piezoelectric sensing elements are electrically connected to integrated circuits provided on the same substrate as the sensing elements. The integrated circuits can be configured to amplify, digitize, calibrate, store, and/or communicate force values electrical terminals to external circuitry.

A mirror device includes a support portion, a movable portion, and a pair of torsion bars disposed on both sides of the movable portion on a first axis. The movable portion includes a frame-shaped frame connected to the pair of torsion bars and a mirror unit disposed inside the frame. The mirror unit is connected to the frame in each of a pair of connection regions located on both sides of the mirror unit in a direction parallel to a second axis. A region other than the pair of connection regions in a region between the mirror unit and the frame is a space. An outer edge of the mirror unit and an inner edge of the frame are connected to each other so that a curvature in each of the pair of connection regions is continuous when viewed from a direction perpendicular to the first and the second axes.

A method for forming a MEMS structure for an inertial sensor from fused silica includes: depositing a conductive layer on one or more selected regions of a first surface of a fused silica substrate, and illuminating areas of the fused silica substrate with laser radiation in a pattern defining features of the MEMS structure for an inertial sensor. A masking layer is deposited at least on the one or more selected regions of the first surface of the fused silica substrate where the conductive layer has been deposited, such that the illuminated areas of the fused silica substrate remain exposed. A first etch of the exposed areas of the fused silica substrate is performed so as to selectively etch the pattern defining features of the MEMS structure for an inertial sensor.

A micro-electro-mechanical system (MEMS) microphone is provided. The MEMS microphone includes a substrate, a diaphragm, a backplate and a first protrusion. The substrate has an opening portion. The diaphragm is disposed on one side of the substrate and extends across the opening portion of the substrate. The backplate includes a plurality of acoustic holes. The backplate is disposed on one side of the diaphragm. An air gap is formed between the backplate and the diaphragm. The first protrusion extends from the backplate towards the air gap.

A piezoelectric microelectromechanical systems device can include a cavity bounded by walls and an asymmetrical bimorph structure at least partially spanning the cavity that includes at least a piezoelectric layer and two electrode layers. The electrode layers can have relative thicknesses configured to compensate for expected temperature stress in the bimorph structure. Thus, metals having different thicknesses can be positioned and configured to compensate deflection due to thermal stress of any or all of the piezoelectric layer, the first metal layer, and second metal layer and a substrate. A method for making the piezoelectric microelectromechanical systems device is also provided.

A piezoelectric microelectromechanical systems diaphragm microphone can be mounted on a printed circuit board. The microphone can include a substrate with an opening between a bottom end of the substrate and a top end of the substrate. The microphone can have two or more piezoelectric film layers disposed over the top end of the substrate and defining a diaphragm structure. Each of the two or more piezoelectric film layers can have a predefined residual stress that substantially cancel each other out so that the diaphragm structure is substantially flat with substantially zero residual stress. The microphone can include one or more electrodes disposed over the diaphragm structure. The diaphragm structure is configured to deflect when the diaphragm is subjected to sound pressure via the opening in the substrate.