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: 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 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 for fabricating a III-nitride based semiconductor device, including (a) growing one or more buffer layers on or above a semi-polar or non-polar GaN substrate, wherein the buffer layers are semi-polar or non-polar III-nitride buffer layers; and (b) doping the buffer layers so that a number of crystal defects in III-nitride device layers formed on or above the doped buffer layers is not higher than a number of crystal defects in III-nitride device layers formed on or above one or more undoped buffer layers. The doping can reduce or prevent formation of misfit dislocation lines and additional threading dislocations. The thickness and/or composition of the buffer layers can be such that the buffer layers have a thickness near or greater than their critical thickness for relaxation. In addition, one or more (AlInGaN) or III-nitride device layers can be formed on or above the buffer layers.

Abstract: A method for fabricating a III-nitride based semiconductor device, including (a) growing one or more buffer layers on or above a semi-polar or non-polar GaN substrate, wherein the buffer layers are semi-polar or non-polar III-nitride buffer layers; and (b) doping the buffer layers so that a number of crystal defects in III-nitride device layers formed on or above the doped buffer layers is not higher than a number of crystal defects in III-nitride device layers formed on or above one or more undoped buffer layers. The doping can reduce or prevent formation of misfit dislocation lines and additional threading dislocations. The thickness and/or composition of the buffer layers can be such that the buffer layers have a thickness near or greater than their critical thickness for relaxation. In addition, one or more (AlInGaN) or III-nitride device layers can be formed on or above the buffer layers.

Abstract: An (AlInGaN) based semiconductor device, comprising a first layer that is a semipolar or nonpolar nitride (AlInGaN) layer having a lattice constant that is partially or fully relaxed, deposited on a substrate or a template, wherein there are one or more dislocations at a heterointerface between the first layer and the substrate or the template; one or more strain compensated layers on the first layer, for defect reduction and stress engineering in the device, that is lattice matched to a larger lattice constant of the first layer; and one or more nonpolar or semipolar (AlInGaN) device layers on the strain compensated layers.

Abstract: An optoelectronic device, comprising an active region and a waveguide structure to provide optical confinement of light emitted from the active region; a pair of facets on opposite ends of the device, having opposite surface polarity; and one of the facets which has been roughened by a crystallographic chemical etching process, wherein the device is a nonpolar or semipolar (Ga,In,Al,B)N based device.

Abstract: A structure for improving the mirror facet cleaving yield of (Ga,Al,In,B)N laser diodes grown on nonpolar or semipolar (Ga,Al,In,B)N substrates. The structure comprises a nonpolar or semipolar (Ga,Al,In,B)N laser diode including a waveguide core that provides sufficient optical confinement for the device's operation in the absence of p-type doped aluminum-containing waveguide cladding layers, and one of more n-type doped aluminum-containing layers that can be used to assist with facet cleaving along a particular crystallographic plane.