Abstract: Method for forming an integrated acoustic device. A thin film piezoelectric acoustic transducer is epitaxially formed on a host substrate and is then transferred to a functional target substrate wherein physical phenomena from the piezoelectric transducer and the arbitrary functional substrate interact to form a hybrid acoustic microsystem comprising the piezoelectric transducer and the arbitrary functional substrate.

Abstract: Acoustic wave devices based on epitaxially grown heterostructures comprising appropriate combinations of epitaxially grown metallic transition metal nitride (TMN) layers, epitaxially grown Group III-nitride (III-N) piezoelectric semiconductor thin film layers, and epitaxially grown perovskite oxide (PO) layers. The devices can include bulk acoustic wave (BAW) devices, surface acoustic wave (SAW) devices, high overtone bulk acoustic resonator (HBAR) devices, and composite devices comprising HBAR devices integrated with high-electron-mobility transistors (HEMTs).

Abstract: Acoustic wave devices based on epitaxially grown heterostructures comprising appropriate combinations of epitaxially grown metallic transition metal nitride (TMN) layers, epitaxially grown Group III-nitride (III-N) piezoelectric semiconductor thin film layers, and epitaxially grown perovskite oxide (PO) layers. The devices can include bulk acoustic wave (BAW) devices, surface acoustic wave (SAW) devices, high overtone bulk acoustic resonator (HBAR) devices, and composite devices comprising HBAR devices integrated with high-electron-mobility transistors (HEMTs).

Abstract: Solid-state devices including a layer of a superconductor material epitaxially grown on a crystalline high thermal conductivity substrate, the superconductor material being one of TiNx, ZrNx, HfNx, VNx, NbNx, TaNx, MoNx, WNx, or alloys thereof, and one or more layers of a semiconducting or insulating or metallic material epitaxially grown on the layer of superconductor material, the semiconducting or insulating material being one of a Group III N material or alloys thereof or a Group 4b N material or SiC or ScN or alloys thereof.

Abstract: A method for integrating epitaxial, metallic transition metal nitride (TMN) layers within a compound semiconductor device structure. The TMN layers have a similar crystal structure to relevant semiconductors of interest such as silicon carbide (SiC) and the Group III-Nitrides (III-Ns) such as gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), and their various alloys. Additionally, the TMN layers have excellent thermal stability and can be deposited in situ with other semiconductor materials, allowing the TMN layers to be buried within the semiconductor device structure to create semiconductor/metal/semiconductor heterostructures and superlattices.

Abstract: A semiconductor device structure including a scandium (Sc)- or yttrium (Y)-containing material layer situated between a substrate and one or more overlying layers. The Sc- or Y-containing material layer serves as an etch-stop during fabrication of one or more devices from overlying layers situated above the Sc- or Y-containing material layer. The Sc- or Y-containing material layer can be grown within an epitaxial group III-nitride device structure for applications such as electronics, optoelectronics, and acoustoelectronics, and can improve the etch-depth accuracy, reproducibility and uniformity.

Abstract: Methods for integrating transition metal oxide (TMO) layers into a compound semiconductor device structure via selective oxidation of transition metal nitride (TMN) layers within the structure.

Abstract: Methods for integrating transition metal oxide (TMO) layers into a compound semiconductor device structure via selective oxidation of transition metal nitride (TMN) layers within the structure.

Abstract: A semiconductor device structure including a scandium (Sc)- or yttrium (Y)-containing material layer situated between a substrate and one or more overlying layers. The Sc- or Y-containing material layer serves as an etch-stop during fabrication of one or more devices from overlying layers situated above the Sc- or Y-containing material layer. The Sc- or Y-containing material layer can be grown within an epitaxial group III-nitride device structure for applications such as electronics, optoelectronics, and acoustoelectronics, and can improve the etch-depth accuracy, reproducibility and uniformity.

Abstract: A method to remove epitaxial semiconductor layers from a substrate by growing an epitaxial sacrificial layer on the substrate where the sacrificial layer is a transition metal nitride (TMN) or a TMN ternary compound, growing one or more epitaxial device layers on the sacrificial layer, and separating the device layers from the substrate by etching the sacrificial layer to completely remove the sacrificial layer without damaging or consuming the substrate or any device layer. Also disclosed are the related semiconductor materials made by this method.

Abstract: A process for fabricating a suspended microelectromechanical system (MEMS) structure comprising epitaxial semiconductor functional layers that are partially or completely suspended over a substrate. A sacrificial release layer and a functional device layer are formed on a substrate. The functional device layer is etched to form windows in the functional device layer defining an outline of a suspended MEMS device to be formed from the functional device layer. The sacrificial release layer is then etched with a selective release etchant to remove the sacrificial release layer underneath the functional layer in the area defined by the windows to form the suspended MEMS structure.

Abstract: A process for fabricating a suspended microelectromechanical system (MEMS) structure comprising epitaxial semiconductor functional layers that are partially or completely suspended over a substrate. A sacrificial release layer and a functional device layer are formed on a substrate. The functional device layer is etched to form windows in the functional device layer defining an outline of a suspended MEMS device to be formed from the functional device layer. The sacrificial release layer is then etched with a selective release etchant to remove the sacrificial release layer underneath the functional layer in the area defined by the windows to form the suspended MEMS structure.

Abstract: A method for integrating epitaxial, metallic transition metal nitride (TMN) layers within a compound semiconductor device structure. The TMN layers have a similar crystal structure to relevant semiconductors of interest such as silicon carbide (SiC) and the Group III-Nitrides (III-Ns) such as gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), and their various alloys. Additionally, the TMN layers have excellent thermal stability and can be deposited in situ with other semiconductor materials, allowing the TMN layers to be buried within the semiconductor device structure to create semiconductor/metal/semiconductor heterostructures and superlattices.

Abstract: A method to remove epitaxial semiconductor layers from a substrate by growing an epitaxial sacrificial layer on the substrate where the sacrificial layer is a transition metal nitride (TMN) or a TMN ternary compound, growing one or more epitaxial device layers on the sacrificial layer, and separating the device layers from the substrate by etching the sacrificial layer to completely remove the sacrificial layer without damaging or consuming the substrate or any device layer. Also disclosed are the related semiconductor materials made by this method.