Abstract: A method for manufacturing a micro-electro-mechanical systems (MEMS) platform is provided. The method includes depositing a piezoelectric layer on a first device layer of a first cavity-embedded silicon-on-insulator (SOI) substrate, wherein the first device layer is N-type doped and comprises a first thickness, polarizing the piezoelectric layer according to a desired pattern, bonding a second device layer comprising a second thickness to the piezoelectric layer, wherein the second device layer is N-type doped, and defining a resonator lateral geometry by forming trenches through the second device layer, the piezoelectric layer, and the first device layer.

Abstract: A laminated ScxAl1-xN BAW resonator with complementary-switchable operation in thickness extensional modes (TEl and TEN). The resonator comprises ferroelectric ScxAl1-xN layers alternatively stacked with metal electrodes, enabling independent polarization switching of each piezoelectric layer. Opting for unanimous or alternative poling of the ScxAl1-xN layers, the resonator can be switched to operate in two complementary states with either TEl or TEN active resonance modes of similarly large kt2.

Abstract: In one aspect, the disclosure relates to a super high frequency (SHF) or extremely high frequency (EHF) bulk acoustic resonator that includes a nanostructure, wherein the nanostructure includes a substrate, a three-dimensional structure disposed on the substrate, wherein the three-dimensional structure includes a planar structure including at least one nanocomponent and a matrix material contacting the nanocomponent on at least one side, the matrix material including an SiGe alloy or Ge. The disclosed bulk acoustic resonator operates at frequencies of from about 100 MHz to about 100 GHz, is capable of self-amplification upon application of direct current or voltage, and has a Q factor amplification exceeding 1. Also disclosed are methods for amplification of mechanical resonance in the disclosed bulk acoustic resonators and devices incorporating the bulk acoustic resonators.

Abstract: Methods and systems are directed to compensating a frequency drift of a mechanical resonator due to temperature change. The method includes, in part, generating a drive voltage and applying the drive voltage to the mechanical resonator, wherein the drive voltage excites elastic nonlinearity of the mechanical resonator and generates a temperature-dependent force or displacement enabling the mechanical resonator to compensate the frequency drift. The drive voltage can have a constant magnitude or a temperature-dependent magnitude. The drive voltage with a constant magnitude may be applied to a piezoelectrically-actuated resonator comprising a piezoelectric layer and a plurality of semiconductor layers, wherein thicknesses of the piezoelectric layer and the plurality of semiconductor layers are designed so that the desired temperature-dependent force or displacement can be generated with the applied drive voltage.

Abstract: An adaptive RF acoustic resonator contains tunable and switchable hybrid surface-bulk acoustic waves (SAW-BAW). The surface and bulk acoustic waves couple for the spectral sensing and configurable filtering. The acoustic resonator includes a piezoelectric or ferroelectric layer, such as a SLAIN layer, which is patterned into interdigital transducers, and an intermediate layer of AlGaN—GaN, which is built on a SiC substrate. The device is protected under a plastic packaging cap. An external tuning voltage applies on the acoustic resonator to generate the tunable frequency and bandwidth of the bulk and surface acoustic waves. An RF switch generates an electric field to suppress a residual polarization during acoustic resonator switching. The bulk acoustic wave excited in the piezoelectric or ferroelectric layer couples with the surface acoustic wave propagating in the intermediate layer. The Sc concentration in the ferroelectric layer exceeds 28%.

Abstract: In one aspect, the disclosure relates to a super high frequency (SHF) or extremely high frequency (EHF) bulk acoustic resonator that includes a nanostructure, wherein the nanostructure includes a substrate, a three-dimensional structure disposed on the substrate, wherein the three-dimensional structure includes a planar structure including at least one nanocomponent and a matrix material contacting the nanocomponent on at least one side, the matrix material including an SiGe alloy or Ge. The disclosed bulk acoustic resonator operates at frequencies of from about 100 MHz to about 100 GHz, is capable of self-amplification upon application of direct current or voltage, and has a Q factor amplification exceeding 1. Also disclosed are methods for amplification of mechanical resonance in the disclosed bulk acoustic resonators and devices incorporating the bulk acoustic resonators.

Abstract: A method for fabricating nano-electro-mechanical tags for identification and authentication includes, in part, forming a protective layer above a substrate, forming a first conductive layer above the protective layer serving as a first electrode, forming a piezoelectric layer above the first conductive layer, forming a second conductive layer above the piezoelectric layer, patterning the second conductive layer to form a second electrode, patterning the piezoelectric layer to expose one or more portions of the first conductive layer, and forming one or more trenches that extends into a plurality layers formed above. In addition, a sacrificial layer can be formed above portions of the substrate, and the sacrificial layer can be removed by etching to release the nano-electro-mechanical tags from the substrate.

Abstract: A laminated ScxAl1-xN BAW resonator with complementary-switchable operation in thickness extensional modes (TEl and TEN). The resonator comprises ferroelectric ScxAl1-xN layers alternatively stacked with metal electrodes, enabling independent polarization switching of each piezoelectric layer. Opting for unanimous or alternative poling of the ScxAl1-xN layers, the resonator can be switched to operate in two complementary states with either TEl or TEN active resonance modes of similarly large kt2.

Abstract: A digitally tunable acoustic wave resonator includes, in part, a first electrode positioned above a substrate, a composite stack positioned above the first electrode, and a second electrode positioned above the composite stack. The composite stack may include one or more alternate layers of a ferroelectric layer and a transition-metal nitride layer. The transition-metal nitride layer can be positioned above the ferroelectric layer, except the ferroelectric layer at the top of the composite stack. The ferroelectric layer comprises an aluminum scandium nitride layer Al1-xScxN, where 0<x<1.

Abstract: An acoustic waveguide having high-Q resonator characteristics is disclosed and a fabrication method is described. Various waveguide-based test-vehicles, implemented in single crystal silicon and transduced by thin aluminum nitride films, are demonstrated. Silicon resonators with type-I and type-II dispersion characteristics are presented to experimentally justify the analytical mode synthesis technique for realization of high quality-factor silicon Lamb wave resonators. An analytical design procedure is also presented for geometrical engineering of the waveguides to realize high-Q resonators without the need for geometrical suspension through narrow tethers or rigid anchors. The effectiveness of the dispersion engineering methodology is verified through development of experimental test-vehicles in 20 ?m-thick single-crystal silicon (SCS) waveguides with 500 nm aluminum nitride transducers.

Abstract: An adaptive filter includes, in part, a linear filter, and a non-linear resonator coupled to the linear filter and adapted to resonate at a frequency that is an integer multiple of the frequency of a received RF signal. The adaptive filter filters out the received RF signal. The resonant frequency may be twice the frequency of the received RF signal. The adaptive filter optionally includes a second non-linear resonator coupled to the linear filter and adapted to resonate at a frequency defined by a sum of the integer multiple of the frequency of the received signal and an offset frequency.

Abstract: A Fin Bulk Acoustic Resonator (FinBAR) includes a fin integrally fabricated on a substrate of a glass or a semiconductor, an inner electrode deposited on the fin, a piezoelectric layer disposed on the inner electrode, an outer electrode deposited on the piezoelectric layer, a first electrode and a second electrode formed on the top surface of the substrate and connected to the inner and outer electrodes respectfully. The fin is characterized with a larger height than its width. A FinBAR array including a number of the FinBARs with different fin widths sequentially located on one chip is capable of continuously filtering frequencies in UHF and SHF bands.

Abstract: A tunable non-reciprocal frequency limiter with an asymmetric micro-electro-mechanical resonator has two independent transducer ports. One port has a film stack including a 10 nm hafnium zirconium oxide (HZO) and another port has a film stack including a 120 nm aluminum nitride (AlN) film. These film stacks are deposited on top of 70 nm single crystal silicon substrate applying CMOS compatible fabrication techniques. The asymmetric transducer architecture with dissimilar electromechanical coupling coefficients force the resonator into mechanical nonlinearity on actuation with transducer having larger coupling. A proof-of-concept electrically-coupled channel filter is demonstrated with two such asymmetric resonators at ˜253 MHz with individual Qres of ˜870 and a non-reciprocal transmission ratio (NTR) ˜16 dB and BW3 dB of 0.25%.

Abstract: A nano-mechanical acoustical resonator is designed and fabricated with CMOS compatible techniques to apply to mm-wave RF front-ends and 5G wireless communication systems which have extreme small scale and integrated in 3D sensors and actuators.

Abstract: An adaptive filter includes, in part, a linear filter, and a non-linear resonator coupled to the linear filter and adapted to resonate at a frequency that is an integer multiple of the frequency of a received RF signal. The adaptive filter filters out the received RF signal. The resonant frequency may be twice the frequency of the received RF signal. The adaptive filter optionally includes a second non-linear resonator coupled to the linear filter and adapted to resonate at a frequency defined by a sum of the integer multiple of the frequency of the received signal and an offset frequency.

Abstract: An adaptive RF acoustic resonator contains tunable and switchable hybrid surface-bulk acoustic waves (SAW-BAW). The surface and bulk acoustic waves couple for the spectral sensing and configurable filtering. The acoustic resonator includes a piezoelectric or ferroelectric layer, such as a SLAIN layer, which is patterned into interdigital transducers, and an intermediate layer of AlGaN—GaN, which is built on a SiC substrate. The device is protected under a plastic packaging cap. An external tuning voltage applies on the acoustic resonator to generate the tunable frequency and bandwidth of the bulk and surface acoustic waves. An RF switch generates an electric field to suppress a residual polarization during acoustic resonator switching. The bulk acoustic wave excited in the piezoelectric or ferroelectric layer couples with the surface acoustic wave propagating in the intermediate layer. The Sc concentration in the ferroelectric layer exceeds 28%.

Abstract: A ferroelectric transducer includes, in part, a first electrode positioned above a substrate; a composite stack positioned above the first electrode, and a second electrode positioned above the composite stack. The composite stack may include one or more alternate layers of a ferroelectric layer and a transition-metal nitride layer. The transition-metal nitride layer can be positioned above a corresponding ferroelectric layer, except the topmost ferroelectric layer in the composite stack. The ferroelectric layer comprises a scandium-doped aluminum nitride (ScxAl1-xN) film, wherein 0<x<1.

Abstract: A digitally tunable acoustic wave resonator includes, in part, a first electrode positioned above a substrate, a composite stack positioned above the first electrode, and a second electrode positioned above the composite stack. The composite stack may include one or more alternate layers of a ferroelectric layer and a transition-metal nitride layer. The transition-metal nitride layer can be positioned above the ferroelectric layer, except the ferroelectric layer at the top of the composite stack. The ferroelectric layer comprises an aluminum scandium nitride layer Al1-xScxN, where 0<x<1.

Abstract: A method for fabricating nano-electro-mechanical tags for identification and authentication includes, in part, forming a protective layer above a substrate, forming a first conductive layer above the protective layer serving as a first electrode, forming a piezoelectric layer above the first conductive layer, forming a second conductive layer above the piezoelectric layer, patterning the second conductive layer to form a second electrode, patterning the piezoelectric layer to expose one or more portions of the first conductive layer, and forming one or more trenches that extends into a plurality layers formed above. In addition, a sacrificial layer can be formed above portions of the substrate, and the sacrificial layer can be removed by etching to release the nano-electro-mechanical tags from the substrate.

Abstract: An acoustically coupled RF filter system includes, in part, a first conductive layer, a ferroelectric layer, and a second conductive layer, wherein the second conductive layer includes a plurality of interdigital transducers (IDTs) formed thereon. The ferroelectric layer can be positioned above the first conductive layer, and there is a semi-trench formed in the ferroelectric layer. The second conductive layer can be positioned above the ferroelectric layer. The plurality of IDTs is formed by patterning the second conductive layer and forms an RF filter input and an RF filter output. The ferroelectric layer comprises Al1-xScxN, wherein 0<x<1.