Abstract: A method of forming a semiconductor structure includes forming an epitaxial semiconductor island having a first material characteristic on a base layer, and growing an epitaxial structure from the epitaxial semiconductor island and the base layer. The epitaxial structure has a second material characteristic that is different from the first material characteristic of the epitaxial semiconductor island. Related semiconductor device structures are also disclosed.

Abstract: An apparatus includes a substrate. The apparatus further includes a group III-nitride buffer layer on the substrate; a group III-nitride barrier layer on the group III-nitride buffer layer, the group III-nitride barrier layer including a higher bandgap than a bandgap of the group III-nitride buffer layer. The apparatus further includes a source electrically coupled to the group III-nitride barrier layer; a gate electrically coupled to the group III-nitride barrier layer; a drain electrically coupled to the group III-nitride barrier layer; and a p-region being at least one of the following: in the substrate or on the substrate below said group III-nitride barrier layer.

Abstract: Transistor devices are provided. In one example, the transistor device includes a channel layer. The transistor device includes a multilayer barrier structure on the channel layer. The transistor device includes a gate contact having a gate length of about 100 nm or less. A ratio of the gate length to a thickness of the multilayer barrier structure is in a range of about 8:1 to about 16:1.

Abstract: An apparatus includes a substrate. The apparatus further includes a group III-nitride buffer layer on the substrate; a group III-nitride barrier layer on the group III-nitride buffer layer, the group III-nitride barrier layer including a higher bandgap than a bandgap of the group III-nitride buffer layer. The apparatus further includes a source electrically coupled to the group III-nitride barrier layer; a gate electrically coupled to the group III-nitride barrier layer; a drain electrically coupled to the group III-nitride barrier layer; and a p-region being at least one of the following: in the substrate or on the substrate below said group III-nitride barrier layer.

Abstract: An apparatus configured to reduce lag includes a substrate; a group III-Nitride back barrier layer on the substrate; a group III-Nitride channel layer on the group III-Nitride back barrier layer; a group III-Nitride barrier layer on the group III-Nitride channel layer, the group III-Nitride barrier layer include a higher bandgap than a bandgap of the group III-Nitride channel layer; a source electrically coupled to the group III-Nitride barrier layer; a gate on the group III-Nitride barrier layer; a drain electrically coupled to the group III-Nitride barrier layer; and a p-region being arranged at or below the group III-Nitride barrier layer. Additionally, at least a portion of the p-region is arranged vertically below at least one of the following: the source, the gate, an area between the gate and the drain.

Abstract: An apparatus includes a substrate. The apparatus further includes a group III-nitride buffer layer on the substrate; a group III-nitride barrier layer on the group III-nitride buffer layer, the group III-nitride barrier layer including a higher bandgap than a bandgap of the group III-nitride buffer layer. The apparatus further includes a source electrically coupled to the group III-nitride barrier layer; a gate electrically coupled to the group III-nitride barrier layer; a drain electrically coupled to the group III-nitride barrier layer; and a p-region being at least one of the following: in the substrate or on the substrate below said group III-nitride barrier layer.

Abstract: An apparatus includes a substrate. The apparatus further includes a group III-nitride buffer layer on the substrate; a group III-nitride barrier layer on the group III-nitride buffer layer, the group III-nitride barrier layer including a higher bandgap than a bandgap of the group III-nitride buffer layer. The apparatus further includes a source electrically coupled to the group III-nitride barrier layer; a gate electrically coupled to the group III-nitride barrier layer; a drain electrically coupled to the group III-nitride barrier layer; and a p-region being at least one of the following: in the substrate or on the substrate below said group III-nitride barrier layer.

Abstract: The disclosure is directed to a high-electron mobility transistor that includes a SiC substrate layer, a GaN buffer layer arranged on the SiC substrate layer, and a p-type material layer having a length parallel to a surface of the SiC substrate layer over which the GaN buffer layer is provided. The p-type material layer is provided in one of the following: the SiC substrate layer and a first layer arranged on the SiC substrate layer. A method of making the high-electron mobility transistor is also disclosed.

Abstract: An apparatus includes a substrate. The apparatus further includes a group III-nitride buffer layer on the substrate; a group III-nitride barrier layer on the group III-nitride buffer layer, the group III-nitride barrier layer including a higher bandgap than a bandgap of the group III-nitride buffer layer. The apparatus further includes a source electrically coupled to the group III-nitride barrier layer; a gate electrically coupled to the group III-nitride barrier layer; a drain electrically coupled to the group III-nitride barrier layer; and a p-region being at least one of the following: in the substrate or on the substrate below said group III-nitride barrier layer.

Abstract: The disclosure is directed to a high-electron mobility transistor that includes a SiC substrate layer, a GaN buffer layer arranged on the SiC substrate layer, and a p-type material layer having a length parallel to a surface of the SiC substrate layer over which the GaN buffer layer is provided. The p-type material layer is provided in one of the following: the SiC substrate layer and a first layer arranged on the SiC substrate layer. A method of making the high-electron mobility transistor is also disclosed.

Abstract: The disclosure is directed to a high-electron mobility transistor that includes a SiC substrate layer, a GaN buffer layer arranged on the SiC substrate layer, and a p-type material layer having a length parallel to a surface of the SiC substrate layer over which the GaN buffer layer is provided. The p-type material layer is provided in one of the following: the SiC substrate layer and a first layer arranged on the SiC substrate layer. A method of making the high-electron mobility transistor is also disclosed.

Abstract: A predisposed high electron mobility transistor (HEMT) is disclosed. The predisposed HEMT includes a buffer layer, a HEMT channel layer on the buffer layer, a first HEMT barrier layer over the HEMT channel layer, and a HEMT cap layer on the first HEMT barrier layer. The HEMT cap layer has a drain region, a source region, and a gate region. Further, the HEMT cap layer has a continuous surface on the drain region, the source region, and the gate region. When no external voltage is applied between the source region and the gate region, the gate region either depletes carriers from the HEMT channel layer or provides carriers to the HEMT channel layer, thereby selecting a predisposed state of the predisposed HEMT.

Abstract: Embodiments of a semi-insulating Group III nitride and methods of fabrication thereof are disclosed. In one embodiment, a semi-insulating Group III nitride layer includes a first doped portion that is doped with a first dopant and a second doped portion that is doped with a second dopant that is different than the first dopant. The first doped portion extends to a first thickness of the semi-insulating Group III nitride layer. The second doped portion extends from approximately the first thickness of the semi-insulating Group III nitride layer to a second thickness of the semi-insulating Group III nitride layer. In one embodiment, the first dopant is Iron (Fe), and the second dopant is Carbon (C). In another embodiment, the semi-insulating Group III nitride layer is a semi-insulating Gallium Nitride (GaN) layer, the first dopant is Fe, and the second dopant is C.

Abstract: Embodiments of a semi-insulating Group III nitride and methods of fabrication thereof are disclosed. In one embodiment, a semi-insulating Group III nitride layer includes a first doped portion that is doped with a first dopant and a second doped portion that is doped with a second dopant that is different than the first dopant. The first doped portion extends to a first thickness of the semi-insulating Group III nitride layer. The second doped portion extends from approximately the first thickness of the semi-insulating Group III nitride layer to a second thickness of the semi-insulating Group III nitride layer. In one embodiment, the first dopant is Iron (Fe), and the second dopant is Carbon (C). In another embodiment, the semi-insulating Group III nitride layer is a semi-insulating Gallium Nitride (GaN) layer, the first dopant is Fe, and the second dopant is C.

Abstract: A predisposed high electron mobility transistor (HEMT) is disclosed. The predisposed HEMT includes a buffer layer, a HEMT channel layer on the buffer layer, a first HEMT barrier layer over the HEMT channel layer, and a HEMT cap layer on the first HEMT barrier layer. The HEMT cap layer has a drain region, a source region, and a gate region. Further, the HEMT cap layer has a continuous surface on the drain region, the source region, and the gate region. When no external voltage is applied between the source region and the gate region, the gate region either depletes carriers from the HEMT channel layer or provides carriers to the HEMT channel layer, thereby selecting a predisposed state of the predisposed HEMT.

Abstract: A wafer including a SiC substrate having a surface that is inclined relative to a (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree, a SiC homoepitaxial device layer, and a SiC homoepitaxial boundary layer having a thickness up to 1 ?m arranged between the substrate and the device layer. The boundary layer has been grown on the substrate under an atmosphere of lower supersaturation than when forming the device layer and at a C/Si ratio above 1.

Abstract: Epitaxial silicon carbide layers are fabricated by forming features in a surface of a silicon carbide substrate having an off-axis orientation toward a crystallographic direction. The features include at least one sidewall that is orientated nonparallel (i.e., oblique or perpendicular) to the crystallographic direction. The epitaxial silicon carbide layer is then grown on the surface of the silicon carbide substrate that includes features therein.

Abstract: A wafer including a SiC substrate having a surface that is inclined relative to a (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree, a SiC homoepitaxial device layer, and a SiC homoepitaxial boundary layer having a thickness up to 1 ?m arranged between the substrate and the device layer. The boundary layer has been grown on the substrate under an atmosphere of lower supersaturation than when forming the device layer and at a C/Si ratio above 1.

Abstract: A method for producing, on an SiC substrate, SiC homoepitaxial layers of the same polytype as the substrate. The layers are grown on a surface of the SiC substrate, wherein the surface is inclined relative to the (0001) basal plane at an angle higher than 0.1 degree but less than 1 degree. An homoepitaxial growth is started by forming a boundary layer with a thickness up to 1 ?m.

Abstract: Epitaxial silicon carbide layers are fabricated by forming features in a surface of a silicon carbide substrate having an off-axis orientation toward a crystallographic direction. The features include at least one sidewall that is orientated nonparallel (i.e., oblique or perpendicular) to the crystallographic direction. The epitaxial silicon carbide layer is then grown on the surface of the silicon carbide substrate that includes features therein.