Abstract: Fabrication methods and gallium nitride transistors, in which an electronic device includes a substrate, a buffer structure, a hetero-epitaxy structure over the buffer structure, and a transistor over or in the hetero-epitaxy structure. In one example, the buffer structure has an extrinsically carbon doped gallium nitride layer over a dual superlattice stack or over a multilayer composition graded aluminum gallium nitride stack, and a silicon nitride cap layer over the hetero-epitaxy structure.

Abstract: Fabrication methods and gallium nitride transistors, in which an electronic device includes a substrate, a buffer structure, a hetero-epitaxy structure over the buffer structure, and a transistor over or in the hetero-epitaxy structure. In one example, the buffer structure has an extrinsically carbon doped gallium nitride layer over a dual superlattice stack or over a multilayer composition graded aluminum gallium nitride stack, and a silicon nitride cap layer over the hetero-epitaxy structure.

Abstract: A method includes depositing a first epitaxial layer of an aluminum gallium nitride (AlGaN) material onto a preliminary substrate and polishing the first layer's surface. Ions are implanted beneath the surface, which is bonded to a seed insulating substrate. Annealing is performed, resulting in second epitaxial layer on preliminary substrate and third epitaxial layer on seed insulating substrate. Third layer's surface is polished to obtain a seed wafer. In some implementations, a fourth epitaxial layer of a second AlGaN material is deposited onto surface of third layer. Fourth layer's surface is polished, and ions are implanted beneath the surface, which is bonded to a product insulating substrate. Annealing is performed, resulting in fifth epitaxial layer on seed insulating substrate and sixth epitaxial layer on product insulating substrate. The sixth layer can be used to obtain an AlGaN product, and the fifth layer can be reused to fabricate additional AlGaN products.

Abstract: Fabrication methods and gallium nitride transistors, in which an electronic device includes a substrate, a buffer structure, a hetero-epitaxy structure over the buffer structure, and a transistor over or in the hetero-epitaxy structure. In one example, the buffer structure has an extrinsically carbon doped gallium nitride layer over a dual superlattice stack or over a multilayer composition graded aluminum gallium nitride stack, and a silicon nitride cap layer over the hetero-epitaxy structure.

Abstract: A method for creating a double Bragg mirror is provided. The method comprises providing a wafer having a plurality of bulk acoustic wave (BAW) devices at an intermediate stage of manufacturing. A first dielectric layer is deposited over the wafer. A plurality of as-deposited thicknesses of the dielectric layer are determined, each as-deposited thickness corresponding to one BAW device from the plurality of BAW devices. A corresponding trimmed dielectric layer over each of the BAW devices is formed by removing a portion of the dielectric layer over each of the BAW devices, with a thickness of the removed portion determined from a corresponding as-deposited thickness and a target thickness. A Bragg acoustic reflector that includes the corresponding trimmed dielectric layer is formed over each of the BAW devices.

Abstract: A method for creating a double Bragg mirror is provided. The method comprises providing a wafer having a plurality of bulk acoustic wave (BAW) devices at an intermediate stage of manufacturing. A first dielectric layer is deposited over the wafer. A plurality of as-deposited thicknesses of the dielectric layer are determined, each as-deposited thickness corresponding to one BAW device from the plurality of BAW devices. A corresponding trimmed dielectric layer over each of the BAW devices is formed by removing a portion of the dielectric layer over each of the BAW devices, with a thickness of the removed portion determined from a corresponding as-deposited thickness and a target thickness. A Bragg acoustic reflector that includes the corresponding trimmed dielectric layer is formed over each of the BAW devices.

Abstract: In some examples, a gallium-based device comprises a substrate layer; a first group-III nitride layer supported by the substrate layer; a second group-III nitride layer supported by the first group-III nitride layer; a tunnel barrier layer supported by the second group-III nitride layer; a passivation layer supported by the tunnel barrier layer; and source, gate, and drain contact structures supported by the first group-III nitride layer.

Abstract: Method of forming a termination angle in a titanium tungsten layer include providing a titanium tungsten layer and applying a photo resist material to the titanium tungsten layer. The photo resist material is exposed under a defocus condition to generate a resist mask, wherein an edge of the exposed photo resist material corresponds to the sloped termination. The titanium tungsten layer is etched with an etching material, wherein the etching material at least partially etches the photo resist material exposed under the defocused condition, and wherein the etching results in the sloped termination in the titanium tungsten layer.

Abstract: The dominant frequency of a solidly mounted resonator (100/280/300/400) is substantially increased by reducing the thickness of each layer of each Bragg acoustic reflector (112/160/224/274) to have a thickness than is substantially equal to one-quarter of the wavelength of a frequency that is a higher harmonic resonant frequency of the fundamental resonant frequency of the solidly mounted resonator (100/280/300/400).

Abstract: A method of fabricating a sloped termination of a molybdenum layer includes providing the molybdenum layer and applying a photo resist material to the molybdenum layer. The photo resist material is exposed under a defocus condition to generate a resist mask having an edge portion. The molybdenum layer is etched at least at the edge portion of the resist mask to result in a sloped termination of the molybdenum layer.

Abstract: Method of forming a termination angle in a titanium tungsten layer include providing a titanium tungsten layer and applying a photo resist material to the titanium tungsten layer. The photo resist material is exposed under a defocus condition to generate a resist mask, wherein an edge of the exposed photo resist material corresponds to the sloped termination. The titanium tungsten layer is etched with an etching material, wherein the etching material at least partially etches the photo resist material exposed under the defocused condition, and wherein the etching results in the sloped termination in the titanium tungsten layer.

Abstract: Method of forming a termination angle in a titanium tungsten layer include providing a titanium tungsten layer and applying a photo resist material to the titanium tungsten layer. The photo resist material is exposed under a defocus condition to generate a resist mask, wherein an edge of the exposed photo resist material corresponds to the sloped termination. The titanium tungsten layer is etched with an etching material, wherein the etching material at least partially etches the photo resist material exposed under the defocused condition, and wherein the etching results in the sloped termination in the titanium tungsten layer.

Abstract: Method of forming a termination angle in a titanium tungsten layer include providing a titanium tungsten layer and applying a photo resist material to the titanium tungsten layer. The photo resist material is exposed under a defocus condition to generate a resist mask, wherein an edge of the exposed photo resist material corresponds to the sloped termination. The titanium tungsten layer is etched with an etching material, wherein the etching material at least partially etches the photo resist material exposed under the defocused condition, and wherein the etching results in the sloped termination in the titanium tungsten layer.

Abstract: A method of fabricating a sloped termination of a molybdenum layer includes providing the molybdenum layer and applying a photo resist material to the molybdenum layer. The photo resist material is exposed under a defocus condition to generate a resist mask having an edge portion. The molybdenum layer is etched at least at the edge portion of the resist mask to result in a sloped termination of the molybdenum layer.

Abstract: The dominant frequency of a solidly mounted resonator (100/280/300/400) is substantially increased by reducing the thickness of each layer of each Bragg acoustic reflector (112/160/224/274) to have a thickness than is substantially equal to one-quarter of the wavelength of a frequency that is a higher harmonic resonant frequency of the fundamental resonant frequency of the solidly mounted resonator (100/280/300/400).

Abstract: A method for forming a through silicon via (TSV) in a substrate comprising: depositing a seed layer in a TSV hole; and annealing the seed layer.