Disclosed are semiconductor structure embodiments of a semiconductor-on-insulator region on a bulk substrate. The semiconductor-on-insulator region includes an upper semiconductor layer above and physically separated from the substrate by insulator-containing cavities (e.g., by dielectric layer and/or a pocket of trapped air, of trapped gas, or under vacuum) and, optionally, by a lower semiconductor layer. Disclosed method embodiments include forming openings that extend vertically through the upper semiconductor layer, through a sacrificial semiconductor layer and, optionally, through a lower semiconductor layer to the substrate. Then, a selective isotropic etch process is performed to form cavities, which extend laterally off the sides of the openings into the sacrificial semiconductor layer. Depending upon the embodiments, different process steps are further performed to form plugs in at least the upper portions of the openings and insulators (including dielectric layers and/or a pocket of trapped air, of trapped gas or under vacuum) in the cavities.

Semiconductor device structures and methods for manufacturing the same are provided. The semiconductor device structure includes a substrate, a first layer and a second layer. The first layer is disposed on and in contact with the substrate. The first layer includes Al.sub.X1Ga.sub.(1-X1)N, wherein 0.5≤X1<1. The second layer is disposed on and in contact with the first layer. The second layer includes Al, Ga and N.

A method for manufacturing a semiconductor element of the present disclosure includes: a step of preparing a substrate; a first element forming step of forming a first semiconductor layer in a first region on a surface of the substrate; a first element separating step of separating the first semiconductor layer from the substrate; and a second element forming step of forming a second semiconductor layer in a second region on the surface of the substrate from which the first semiconductor layer is separated. Additionally, in the method for manufacturing a semiconductor element of the present disclosure, at least a portion of the second region overlaps the first region.

A III-nitride-based semiconductor device is provided. The III-nitride semiconductor device includes a silicon substrate having a surface with a periodic array of recesses formed therein. A discontinuous insulating layer is formed within each recess of the periodic array of recesses such that a portion of the silicon substrate surface between adjacent recesses is free from coverage of the discontinuous insulating layer. A first epitaxial III-nitride semiconductor layer is formed over the silicon substrate with the periodic array of recesses and discontinuous insulating layer formed thereon. A second III-nitride semiconductor layer is disposed over the first III-nitride semiconductor layer and has a bandgap greater than a bandgap of the first III-nitride semiconductor layer. At least one source and at least one drain are disposed over the second III-nitride semiconductor layer. A gate is also disposed over the second III-nitride semiconductor layer between the source and the drain.

A method of removing a substrate from III-nitride based semiconductor layers with a cleaving technique. A growth restrict mask is formed on or above a substrate, and one or more III-nitride based semiconductor layers are grown on or above the substrate using the growth restrict mask. The III-nitride based semiconductor layers are bonded to a support substrate or film, and the III-nitride based semiconductor layers are removed from the substrate using a cleaving technique on a surface of the substrate. Stress may be applied to the III-nitride based semiconductor layers, due to differences in thermal expansion between the III-nitride substrate and the support substrate or film bonded to the III-nitride based semiconductor layers, before the III-nitride based semiconductor layers are removed from the substrate. Once removed, the substrate can be recycled, resulting in cost savings for device fabrication.

Techniques related to forming low defect density III-N films, device structures, and systems incorporating such films are discussed. Such techniques include epitaxially growing a first crystalline III-N structure within an opening of a first dielectric layer and extending onto the first dielectric layer, forming a second dielectric layer over the first dielectric layer and laterally adjacent to a portion of the first structure, and epitaxially growing a second crystalline III-N structure extending laterally onto a region of the second dielectric layer.

A group-III-nitride structure and a manufacturing method thereof are provided. In the manufacturing method, one or more grooves are formed by etching a first group-III-nitride epitaxial layer with a patterned first mask layer as a mask; then a second mask layer is formed at least on one or more bottom walls of the one or more grooves, and a first epitaxial growth is performed on the first group-III-nitride epitaxial layer to laterally grow and form a second group-III-nitride epitaxial layer with the second mask layer as a mask, where the one or more grooves are filled with the second group III-nitride epitaxial layer; a second epitaxial growth is then performed on the second group-III-nitride epitaxial layer to grow and form a third group-III-nitride epitaxial layer on the second group-III-nitride epitaxial layer and the patterned first mask layer.

A nitride semiconductor structure includes a Group III nitride semiconductor portion and a Group II-IV nitride semiconductor portion. The Group III nitride semiconductor portion is single crystalline. The Group III nitride semiconductor portion has a predetermined crystallographic plane. The Group II-IV nitride semiconductor portion is provided on the predetermined crystallographic plane of the Group III nitride semiconductor portion. The Group II-IV nitride semiconductor portion is single crystalline. The Group II-IV nitride semiconductor portion contains a Group II element and a Group IV element. The Group II-IV nitride semiconductor portion forms a heterojunction with the Group III nitride semiconductor portion. The predetermined crystallographic plane is a crystallographic plane other than a (0001) plane.

A process for the production of a layer structure of a nitride semiconductor component on a silicon surface, comprising: provision of a substrate having a silicon surface; deposition of an aluminium-containing nitride nucleation layer on the silicon surface of the substrate; optional: deposition of an aluminium-containing nitride buffer layer on the nitride nucleation layer; deposition of a masking layer on the nitride nucleation layer or, if present, on the first nitride buffer layer; deposition of a gallium-containing first nitride semiconductor layer on the masking layer, wherein the masking layer is deposited in such a way that, in the deposition step of the first nitride semiconductor layer, initially separate crystallites grow that coalesce above a coalescence layer thickness and occupy an average surface area of at least 0.16 μm.sup.2 in a layer plane of the coalesced nitride semiconductor layer that is perpendicular to the growth direction.

The invention relates to a method for fabricating a semiconductor structure. The method comprises fabricating a photonic crystal structure of a first material, in particular a first semiconductor material and selectively removing the first material within a predefined part of the photonic crystal structure. The method further comprises replacing the first material within the predefined part of the photonic crystal structure with one or more second materials by selective epitaxy. The one or more second materials may be in particular semiconductor materials. The invention further relates to devices obtainable by such a method.