A gallium nitride substrate comprising a first main surface and a second main surface opposite thereto, wherein the first main surface is a non-polar or semi-polar plane, a dislocation density measured by a room-temperature cathode luminescence method in the first main surface is 1×10.sup.4 cm.sup.−2 or less, and an averaged dislocation density measured by a room-temperature cathode luminescence method in an optional square region sizing 250 μm×250 μm in the first main plan is 1×10.sup.6 cm.sup.−2 or less.

Provided is a thin film transistor including a highly-textured dielectric layer, an active layer, a gate electrode and a source/drain electrode that are stacked on a base substrate. The source/drain electrode includes a source electrode and a drain electrode. The gate electrode and the active layer are insulated from each other. The source electrode and the drain electrode are electrically connected to the active layer. Constituent particles of the active layer are of monocrystalline silicon-like structures. According to the present disclosure, the highly-textured dielectric layer is adopted to replace an original buffer layer to induce the active layer to grow into a monocrystalline silicon-like structure, such that the performance of the thin film transistor is improved.

An engineered substrate structure includes a ceramic substrate having a front surface characterized by a plurality of peaks. The ceramic substrate includes a polycrystalline material. The engineered substrate structure also includes a planarization layer comprising a planarization layer material and coupled to the front surface of the ceramic substrate. The planarization layer defines fill regions filled with the planarization layer material between adjacent peaks of the plurality of peaks on the front surface of the ceramic substrate. The engineered substrate structure further includes a barrier shell encapsulating the ceramic substrate and the planarization layer, wherein the barrier shell has a front side and a back side, a bonding layer coupled to the front side of the barrier shell, a single crystal layer coupled to the bonding layer, and a conductive layer coupled to the back side of the barrier shell.

A device including a non-polarization material includes a number of layers. A first layer of silicon (100) defines a U-shaped groove having a bottom portion (100) and silicon sidewalls (111) at an angle to the bottom portion (100). A second layer of a patterned dielectric on top of the silicon (100) defines vertical sidewalls of the U-shaped groove. A third layer of a buffer covers the first layer and the second layer. A fourth layer of gallium nitride is deposited on the buffer within the U-shaped groove, the fourth layer including cubic gallium nitride (c-GaN) formed at merged growth fronts of hexagonal gallium nitride (h-GaN) that extend from the silicon sidewalls (111), wherein a deposition thickness (h) of the gallium nitride above the first layer of silicon (100) is such that the c-GaN completely covers the h-GaN between the vertical sidewalls.

A first semiconductor layer, a second semiconductor layer, a channel layer, a barrier layer, and a third semiconductor layer are crystal-grown in this order on a first substrate in the +c axis direction, a second substrate is bonded to the side of the barrier layer of the first substrate, and after that, the first substrate is removed, and the first semiconductor layer is selectively thermally decomposed by heating.

A multilayer structure including a hexagonal epitaxial layer, such as GaN or other group III-nitride (III-N) semiconductors, a <111> oriented textured layer, and a non-single crystal substrate, and methods for making the same. The textured layer has a crystalline alignment preferably formed by the ion-beam assisted deposition (IBAD) texturing process and can be biaxially aligned. The in-plane crystalline texture of the textured layer is sufficiently low to allow growth of high quality hexagonal material, but can still be significantly greater than the required in-plane crystalline texture of the hexagonal material. The IBAD process enables low-cost, large-area, flexible metal foil substrates to be used as potential alternatives to single-crystal sapphire and silicon for manufacture of electronic devices, enabling scaled-up roll-to-roll, sheet-to-sheet, or similar fabrication processes to be used. The user is able to choose a substrate for its mechanical and thermal properties, such as how well its coefficient of thermal expansion matches that of the hexagonal epitaxial layer, while choosing a textured layer that more closely lattice matches that layer.

A semiconductor substrate is a provided and an insulating layer is formed thereon. A cavity structure is formed above the insulating layer, including a lateral growth channel and a fin seed structure arranged in the lateral growth channel. The fin seed structure provides a seed surface for growing a fin structure. One or more first semiconductor structures of a first semiconductor material and one or more second semiconductor structures of a second, different, semiconductor material are grown sequentially in the growth channel from the seed surface in an alternating way. The first semiconductor structures provide a seed surface for the second semiconductor structures and the second semiconductor structures provide a seed surface for the first semiconductor structures. The second semiconductor structures are selectively etched, thereby forming the fin structure comprising a plurality of parallel fins of the first semiconductor structures. Corresponding semiconductor structures are also included.

A method for producing a composite silicon carbide structure comprises: providing an initial substrate of monocrystalline silicon carbide; depositing an intermediate layer of polycrystalline silicon carbide at a temperature higher than 1000° C. on the initial substrate, the intermediate layer having a thickness greater than or equal to 1.5 microns; implanting light ionic species through the intermediate layer to form a buried brittle plane in the initial substrate, delimiting the thin layer between the buried brittle plane and the intermediate layer, and depositing an additional layer of polycrystalline silicon carbide at a temperature higher than 1000° C. on the intermediate layer, the intermediate layer and the additional layer forming a carrier substrate, and separating the buried brittle plane during the deposition of the additional layer.

A multilayer semiconductor on insulator structure is provided in which the handle substrate and an epitaxial layer in interfacial contact with the handle substrate comprise electrically active dopants of opposite type. The epitaxial layer is depleted by the handle substrate free carriers, thereby resulting in a high apparent resistivity, which improves the function of the structure in RF devices.

According to one embodiment, a semiconductor device is provided with a first single crystal layer, a polycrystalline layer provided on an entire surface of the first single crystal layer, and a second single crystal layer bonded to the polycrystalline layer. The coefficient of thermal expansion of the polycrystalline layer is greater than the coefficient of thermal expansion of the second single crystal layer, and is smaller than the coefficient of thermal expansion of a compound semiconductor layer which can be provided on the second single crystal layer using an intervening a buffer layer.