Abstract: A method of growing a III-nitride-based epitaxial structure is disclosed. The method includes forming a GaN-based drift layer coupled to the GaN-based substrate, where forming the GaN-based drift layer comprises doping the drift layer with indium to cause the indium concentration of the drift layer to be less than about 1×1016 cm?3 and to cause the carbon concentration of the drift layer to be less than about 1×1016 cm?3. The method also includes forming an n-type channel layer coupled to the GaN-based drift layer, forming an n-contact layer coupled to the GaN-based drift layer, and forming a second electrical contact electrically coupled to the n-contact layer.

Abstract: An integrated device including a vertical III-nitride FET and a Schottky diode includes a drain comprising a first III-nitride material, a drift region comprising a second III-nitride material coupled to the drain and disposed adjacent to the drain along a vertical direction, and a channel region comprising a third III-nitride material coupled to the drift region. The integrated device also includes a gate region at least partially surrounding the channel region, a source coupled to the channel region, and a Schottky contact coupled to the drift region. The channel region is disposed between the drain and the source along the vertical direction such that current flow during operation of the vertical III-nitride FET and the Schottky diode is along the vertical direction.

Abstract: A vertical III-nitride field effect transistor includes a drain comprising a first III-nitride material, a drain contact electrically coupled to the drain, and a drift region comprising a second III-nitride material coupled to the drain. The field effect transistor also includes a channel region comprising a third III-nitride material coupled to the drain and disposed adjacent to the drain along a vertical direction, a gate region at least partially surrounding the channel region, having a first surface coupled to the drift region and a second surface on a side of the gate region opposing the first surface, and a gate contact electrically coupled to the gate region. The field effect transistor further includes a source coupled to the channel region and a source contact electrically coupled to the source.

Abstract: An electronic device includes a III-V substrate having a hexagonal crystal structure and a normal to a growth surface characterized by a misorientation from the <0001> direction of between 0.15° and 0.65°. The electronic device also includes a first epitaxial layer coupled to the III-V substrate and a second epitaxial layer coupled to the first epitaxial layer. The electronic device further includes a first contact in electrical contact with the substrate and a second contact in electrical contact with the second epitaxial layer.

Abstract: A vertical III-nitride field effect transistor includes a drain comprising a first III-nitride material, a drain contact electrically coupled to the drain, and a drift region comprising a second III-nitride material coupled to the drain. The field effect transistor also includes a channel region comprising a third III-nitride material coupled to the drain and disposed adjacent to the drain along a vertical direction, a gate region at least partially surrounding the channel region, having a first surface coupled to the drift region and a second surface on a side of the gate region opposing the first surface, and a gate contact electrically coupled to the gate region. The field effect transistor further includes a source coupled to the channel region and a source contact electrically coupled to the source.

Abstract: A method of growing a III-nitride-based epitaxial structure includes providing a substrate in an epitaxial growth reactor and heating the substrate to a predetermined temperature. The method also includes flowing a gallium-containing gas into the epitaxial growth reactor and flowing a nitrogen-containing gas into the epitaxial growth reactor. The method further includes flowing a gettering gas into the epitaxial growth reactor. The predetermined temperature is greater than 1000° C.

Abstract: An integrated device including a vertical III-nitride FET and a Schottky diode includes a drain comprising a first III-nitride material, a drift region comprising a second III-nitride material coupled to the drain and disposed adjacent to the drain along a vertical direction, and a channel region comprising a third III-nitride material coupled to the drift region. The integrated device also includes a gate region at least partially surrounding the channel region, a source coupled to the channel region, and a Schottky contact coupled to the drift region. The channel region is disposed between the drain and the source along the vertical direction such that current flow during operation of the vertical III-nitride FET and the Schottky diode is along the vertical direction.

Abstract: A method of forming a doped region in a III-nitride substrate includes providing the III-nitride substrate and forming a masking layer having a predetermined pattern and coupled to a portion of the III-nitride substrate. The III-nitride substrate is characterized by a first conductivity type and the predetermined pattern defines exposed regions of the III-nitride substrate. The method also includes heating the III-nitride substrate to a predetermined temperature and placing a dual-precursor gas adjacent the exposed regions of the III-nitride substrate. The dual-precursor gas includes a nitrogen source and a dopant source. The method further includes maintaining the predetermined temperature for a predetermined time period, forming p-type III-nitride regions adjacent the exposed regions of the III-nitride substrate, and removing the masking layer.

Abstract: A semiconductor structure includes a III-nitride substrate characterized by a first conductivity type and having a first side and a second side opposing the first side, a III-nitride epitaxial layer of the first conductivity type coupled to the first side of the III-nitride substrate, and a plurality of III-nitride epitaxial structures of a second conductivity type coupled to the III-nitride epitaxial layer. The semiconductor structure further includes a III-nitride epitaxial formation of the first conductivity type coupled to the plurality of III-nitride epitaxial structures, and a metallic structure forming a Schottky contact with the III-nitride epitaxial formation and coupled to at least one of the plurality of III-nitride epitaxial structures.

Abstract: An edge terminated semiconductor device is described including a GaN substrate; a doped GaN epitaxial layer grown on the GaN substrate including an ion-implanted insulation region, wherein the ion-implanted region has a resistivity that is at least 90% of maximum resistivity and a conductive layer, such as a Schottky metal layer, disposed over the GaN epitaxial layer, wherein the conductive layer overlaps a portion of the ion-implanted region. A Schottky diode is prepared using the Schottky contact structure.

Abstract: A Schottky diode and method of fabricating the Schottky diode using gallium nitride (GaN) materials is disclosed. The method includes providing an n-type GaN substrate having first and second opposing surfaces. The method also includes forming an ohmic metal contact electrically coupled to the first surface, forming an n-type GaN epitaxial layer coupled to the second surface, and forming an n-type aluminum gallium nitride (AlGaN) surface layer coupled to the n-type GaN epitaxial layer. The AlGaN surface layer has a thickness which is less than a critical thickness, and the critical thickness is determined based on an aluminum mole fraction of the AlGaN surface layer. The method also includes forming a Schottky contact electrically coupled to the n-type AlGaN surface layer, where, during operation, an interface between the n-type GaN epitaxial layer and the n-type AlGaN surface layer is substantially free from a two-dimensional electron gas.

Abstract: A method for fabricating a merged p-i-n Schottky (MPS) diode in gallium nitride (GaN) based materials includes providing an n-type GaN-based substrate having a first surface and a second surface. The method also includes forming an n-type GaN-based epitaxial layer coupled to the first surface of the n-type GaN-based substrate, and forming a p-type GaN-based epitaxial layer coupled to the n-type GaN-based epitaxial layer. The method further includes removing portions of the p-type GaN-based epitaxial layer to form a plurality of dopant sources, and regrowing a GaN-based epitaxial layer including n-type material in regions overlying portions of the n-type GaN-based epitaxial layer, and p-type material in regions overlying the plurality of dopant sources. The method also includes forming a first metallic structure electrically coupled to the regrown GaN-based epitaxial layer.

Abstract: A method of growing an n-type III-nitride-based epitaxial layer includes providing a substrate in an epitaxial growth reactor, forming a masking material coupled to a portion of a surface of the substrate, and flowing a first gas into the epitaxial growth reactor. The first gas includes a group III element and carbon. The method further comprises flowing a second gas into the epitaxial growth reactor. The second gas includes a group V element, and a molar ratio of the group V element to the group III element is at least 5,000. The method also includes growing the n-type III-nitride-based epitaxial layer.

Abstract: A method of forming a doped region in a III-nitride substrate includes providing the III-nitride substrate and forming a masking layer having a predetermined pattern and coupled to a portion of the III-nitride substrate. The III-nitride substrate is characterized by a first conductivity type and the predetermined pattern defines exposed regions of the III-nitride substrate. The method also includes heating the III-nitride substrate to a predetermined temperature and placing a dual-precursor gas adjacent the exposed regions of the III-nitride substrate. The dual-precursor gas includes a nitrogen source and a dopant source. The method further includes maintaining the predetermined temperature for a predetermined time period, forming p-type III-nitride regions adjacent the exposed regions of the III-nitride substrate, and removing the masking layer.

Abstract: A semiconductor structure includes a III-nitride substrate with a first side and a second side opposing the first side. The III-nitride substrate is characterized by a first conductivity type and a first dopant concentration. The semiconductor structure also includes a III-nitride epitaxial structure including a first III-nitride epitaxial layer coupled to the first side of the III-nitride substrate and a plurality of III-nitride regions of a second conductivity type. The plurality of III-nitride regions have at least one III-nitride epitaxial region of the first conductivity type between each of the plurality of III-nitride regions. The semiconductor structure further includes a first metallic structure electrically coupled to one or more of the plurality of III-nitride regions and the at least one III-nitride epitaxial region. A Schottky contact is created between the first metallic structure and the at least one III-nitride epitaxial region.

Abstract: A method of fabricating a Schottky diode using gallium nitride (GaN) materials includes providing an n-type GaN substrate having a first surface and a second surface. The second surface opposes the first surface. The method also includes forming an ohmic metal contact electrically coupled to the first surface of the n-type GaN substrate and forming an n-type GaN epitaxial layer coupled to the second surface of the n-type GaN substrate. The method further includes forming an n-type aluminum gallium nitride (AlGaN) surface layer coupled to the n-type GaN epitaxial layer and forming a Schottky contact electrically coupled to the n-type AlGaN surface layer.

Abstract: A method for fabricating an edge termination structure includes providing a substrate having a first surface and a second surface and a first conductivity type, forming a first GaN epitaxial layer of the first conductivity type coupled to the first surface of the substrate, and forming a second GaN epitaxial layer of a second conductivity type opposite to the first conductivity type. The second GaN epitaxial layer is coupled to the first GaN epitaxial layer. The method also includes implanting ions into a first region of the second GaN epitaxial layer to electrically isolate a second region of the second GaN epitaxial layer from a third region of the second GaN epitaxial layer. The method further includes forming an active device coupled to the second region of the second GaN epitaxial layer and forming the edge termination structure coupled to the third region of the second GaN epitaxial layer.

Abstract: A semiconductor structure includes a III-nitride substrate with a first side and a second side opposing the first side. The III-nitride substrate is characterized by a first conductivity type and a first dopant concentration. The semiconductor structure also includes a III-nitride epitaxial structure including a first III-nitride epitaxial layer coupled to the first side of the III-nitride substrate and a plurality of III-nitride regions of a second conductivity type. The plurality of III-nitride regions have at least one III-nitride epitaxial region of the first conductivity type between each of the plurality of III-nitride regions. The semiconductor structure further includes a first metallic structure electrically coupled to one or more of the plurality of III-nitride regions and the at least one III-nitride epitaxial region. A Schottky contact is created between the first metallic structure and the at least one III-nitride epitaxial region.

Abstract: A vertical JFET includes a GaN substrate comprising a drain of the JFET and a plurality of patterned epitaxial layers coupled to the GaN substrate. A distal epitaxial layer comprises a first part of a source channel and adjacent patterned epitaxial layers are separated by a gap having a predetermined distance. The vertical JFET also includes a plurality of regrown epitaxial layers coupled to the distal epitaxial layer and disposed in at least a portion of the gap. A proximal regrown epitaxial layer comprises a second part of the source channel. The vertical JFET further includes a source contact passing through portions of a distal regrown epitaxial layer and in electrical contact with the source channel, a gate contact in electrical contact with a distal regrown epitaxial layer, and a drain contact in electrical contact with the GaN substrate.

Abstract: An integrated device including a vertical III-nitride FET and a Schottky diode includes a drain comprising a first III-nitride material, a drift region comprising a second III-nitride material coupled to the drain and disposed adjacent to the drain along a vertical direction, and a channel region comprising a third III-nitride material coupled to the drift region. The integrated device also includes a gate region at least partially surrounding the channel region, a source coupled to the channel region, and a Schottky contact coupled to the drift region. The channel region is disposed between the drain and the source along the vertical direction such that current flow during operation of the vertical III-nitride FET and the Schottky diode is along the vertical direction.