Abstract: A TPoS resonator includes a substrate and a resonator body suspended over the substrate by at least a first pair of fixed supports (e.g., tethers) that attach to first and second ends of the resonator body. The resonator body includes monocrystalline silicon, which has a [100] crystallographic orientation that is offset by ±? degrees relative to a nodal line of the resonator body (e.g., tether-to-tether axis) when the resonator body is operating at a resonant frequency, where a is a real number in a range from about 5 to about 19 and, more preferably, in a range from about 7 to about 17. The resonator may be an extensional-mode resonator and the resonator body may be rectangular-shaped with unequal length and width dimensions.

Abstract: Methods of forming micromechanical resonators include forming first and second substrates having first and second semiconductor layers of first and second conductivity type therein, respectively. The first semiconductor layer of first conductivity type is bonded to the second semiconductor layer of second conductivity type to thereby define a first rectifying junction at an interface of the bonded semiconductor layers. A piezoelectric layer is formed on the first rectifying junction and at least a first electrode is formed on the piezoelectric layer.

Abstract: A periodic signal generator is configured to generate high frequency signals characterized by relatively low temperature coefficients of frequency (TCF). This generator may include an oscillator containing a pair of equivalent MEMs resonators therein, which are configured to support bulk acoustic wave and surface wave modes of operation at different resonance frequencies. Each resonator includes a stack of layers including a semiconductor resonator body (e.g., Si-body), a piezoelectric layer (e.g., AIN layer) on the resonator body and interdigitated drive and sense electrodes on the piezoelectric layer. The oscillator is configured to support the generation of first and second periodic signals having unequal first and second frequencies (f1, f2) from first and second resonators within the pair. These first and second periodic signals are characterized by respective first and second temperature coefficients of frequency (TCf1, TCf2), which may differ by at least about 10 ppm/° C.

Abstract: A microelectromechanical resonator includes a resonator body anchored to a substrate by at least a pair of tethers that suspend the resonator body opposite an underlying opening in the substrate. A first thermally-actuated tuning beam is provided, which is mechanically coupled to a first portion of the resonator body that is spaced apart from the pair of tethers. The first thermally-actuated tuning beam is configured to induce a mechanical stress in the resonator body by establishing a thermal expansion difference between the first thermally-actuated tuning beam and the resonator body in response to a passing of current through the first thermally-actuated tuning beam.

Abstract: Methods of forming electro-micromechanical resonators provide passive temperature compensation of semiconductor device layers used therein. A first substrate is provided that includes a first electrically insulating temperature compensation layer on a first semiconductor device layer. A step is performed to bond the first electrically insulating temperature compensation layer to a second substrate containing the second electrically insulating temperature compensation layer therein, to thereby form a relatively thick temperature compensation layer. A piezoelectric layer is formed on the first electrically insulating temperature compensation layer and at least a first electrode is formed on the piezoelectric layer.

Abstract: Methods of forming packaged microelectromechanical resonators include forming a first isolation trench in a first surface of a capping substrate, with the first isolation trench encircling a first portion of the capping substrate. The first isolation trench is filled with an electrically insulating material. The first surface of the capping substrate is bonded to a device substrate, which includes the microelectromechanical resonator and at least a first electrically conductive line connected to the microelectromechanical resonator. A second surface of the capping substrate is planarized for a sufficient duration to thereby expose the electrically insulating material and the first portion of the capping substrate encircled by the first isolation trench. The exposed first portion of the capping substrate is selectively etched to thereby define a through-substrate opening therein, which exposes a first portion of the first electrically conductive line.

Abstract: Methods of forming substrates having two-sided microstructures therein include selectively etching a first surface of the substrate to define a plurality of alignment keys therein that extend through the substrate to a second surface thereof. A direct photolithographic alignment step is then performed on a second surface of the substrate by aligning a photolithography mask to the plurality of alignment keys at the second surface. This direct alignment step is performed during steps to photolithographically define patterns in the second surface.

Abstract: A tuneable film bulk acoustic resonator (FBAR) device. The FBAR device includes a bottom electrode, a top electrode and a piezoelectric layer in between the bottom electrode and the top electrode. The piezoelectric layer has a first overlap with the bottom electrode, where the first overlap is defined by a projection of the piezoelectric layer onto the bottom electrode in a direction substantially perpendicular to a plane of the bottom electrode. The FBAR device also includes a first dielectric layer in between the piezoelectric layer and the bottom electrode and a mechanism for reversibly varying an internal impedance of the device, so as to tune a resonant frequency of the FBAR device.

Abstract: A tuneable film bulk acoustic resonator (FBAR) device. The FBAR device includes a bottom electrode, a top electrode and a piezoelectric layer in between the bottom electrode and the top electrode. The piezoelectric layer has a first overlap with the bottom electrode, where the first overlap is defined by a projection of the piezoelectric layer onto the bottom electrode in a direction substantially perpendicular to a plane of the bottom electrode. The FBAR device also includes a first dielectric layer in between the piezoelectric layer and the bottom electrode and a mechanism for reversibly varying an internal impedance of the device, so as to tune a resonant frequency of the FBAR device.