Abstract: A semiconductor structure includes a III-nitride substrate and a drift region coupled to the III-nitride substrate along a growth direction. The semiconductor substrate also includes a channel region coupled to the drift region. The channel region is defined by a channel sidewall disposed substantially along the growth direction. The semiconductor substrate further includes a gate region disposed laterally with respect to the channel region.

Abstract: A method for fabricating a vertical GaN power device includes providing a first GaN material having a first conductivity type and forming a second GaN material having a second conductivity type and coupled to the first GaN material to create a junction. The method further includes implanting ions through the second GaN material and into a first portion of the first GaN material to increase a doping concentration of the first conductivity type. The first portion of the junction is characterized by a reduced breakdown voltage relative to a breakdown voltage of a second portion of the junction.

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 further includes a III-nitride epitaxial layer of the first conductivity type coupled to the first surface of the III-nitride substrate, a first metallic structure electrically coupled to the second surface of the III-nitride substrate, and a III-nitride epitaxial structure of a second conductivity type coupled to the III-nitride epitaxial layer. The III-nitride epitaxial structure comprises at least one edge termination structure.

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 and disposed adjacent to the drain along a vertical direction. The field effect transistor also includes a channel region comprising a third III-nitride material coupled to the drift region, a gate region at least partially surrounding the channel region, 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. 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 field effect transistor is along the vertical direction.

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 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 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 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 layer of the first conductivity type coupled to the first surface of the III-nitride substrate, and a first metallic structure electrically coupled to the second surface of the III-nitride substrate. The semiconductor structure further includes an AlGaN epitaxial layer coupled to the III-nitride epitaxial layer of the first conductivity type, and a III-nitride epitaxial structure of a second conductivity type coupled to the AlGaN epitaxial layer. The III-nitride epitaxial structure comprises at least one edge termination structure.

Abstract: A semiconductor device includes a III-nitride substrate having a first conductivity type and a first electrode electrically coupled to the III-nitride substrate. The semiconductor device also includes a III-nitride material having a second conductivity type coupled to the III-nitride substrate at a regrowth interface and a p-n junction disposed between the III-nitride substrate and the regrowth interface.

Abstract: A method of regrowing material includes providing a III-nitride structure including a masking layer and patterning the masking layer to form an etch mask. The method also includes removing, using an in-situ etch, a portion of the III-nitride structure to expose a regrowth region and regrowing a III-nitride material in the regrowth region.

Abstract: A method for fabricating a lateral gallium nitride (GaN) field-effect transistor includes forming a first and second GaN layer coupled to a substrate, removing a first portion of the second GaN layer to expose a portion of the first GaN layer, and forming a third GaN layer coupled to the second GaN layer and the exposed portion of the first GaN layer. The method also includes removing a portion of the third GaN layer to expose a portion of the second GaN layer, forming a source structure coupled to the third GaN layer. A first portion of the second GaN layer is disposed between the source structure and the second GaN layer. A drain structure is formed that is coupled to the third GaN layer or alternatively to the substrate. The method also includes forming a gate structure coupled to the third GaN layer such that a second portion of the third GaN layer is disposed between the gate structure and the second GaN layer.

Abstract: A semiconductor device includes a III-nitride substrate, a first III-nitride epitaxial layer coupled to the III-nitride substrate and having a mesa, and a second III-nitride epitaxial layer coupled to a top surface of the mesa. The semiconductor device further includes a III-nitride gate structure coupled to a side surface of the mesa, and a spacer configured to provide electrical insulation between the second III-nitride epitaxial layer and the III-nitride gate structure.

Abstract: A vertical JFET includes a III-nitride substrate and a III-nitride epitaxial layer of a first conductivity type coupled to the III-nitride substrate. The first III-nitride epitaxial layer has a first dopant concentration. The vertical JFET also includes a III-nitride epitaxial structure coupled to the first III-nitride epitaxial layer. The III-nitride epitaxial structure includes a set of channels of the first conductivity type and having a second dopant concentration, a set of sources of the first conductivity type, having a third dopant concentration greater than the first dopant concentration, and each characterized by a contact surface, and a set of regrown gates interspersed between the set of channels. An upper surface of the set of regrown gates is substantially coplanar with the contact surfaces of the set of sources.

Abstract: A method for fabricating a vertical gallium nitride (GaN) power device can include providing a GaN substrate with a top surface and a bottom surface, forming a device layer coupled to the top surface of the GaN substrate, and forming a metal contact on a top surface of the vertical GaN power device. The method can further include forming a backside metal by forming an adhesion layer coupled to the bottom surface of the GaN substrate, forming a diffusion barrier coupled to the adhesion layer, and forming a protection layer coupled to the diffusion barrier. The vertical GaN power device can be configured to conduct electricity between the metal contact and the backside metal.

Abstract: A diode includes a substrate characterized by a first dislocation density and a first conductivity type, a first contact coupled to the substrate, and a masking layer having a predetermined thickness and coupled to the semiconductor substrate. The masking layer comprises a plurality of continuous sections and a plurality of openings exposing the substrate and disposed between the continuous sections. The diode also includes an epitaxial layer greater than 5 ?m thick coupled to the substrate and the masking layer. The epitaxial layer comprises a first set of regions overlying the plurality of openings and characterized by a second dislocation density and a second set of regions overlying the set of continuous sections and characterized by a third dislocation density less than the first dislocation density and the second dislocation density. The diode further includes a second contact coupled to the epitaxial layer.

Abstract: An MPS diode includes a III-nitride substrate characterized by a first conductivity type and a first dopant concentration and having a first side and a second side. The MPS diode also includes a III-nitride epitaxial structure comprising a first III-nitride epitaxial layer coupled to the first side of the substrate, wherein a region of the first III-nitride epitaxial layer comprises an array of protrusions. The III-nitride epitaxial structure also includes a plurality of III-nitride regions of a second conductivity type, each partially disposed between adjacent protrusions. Each of the plurality of III-nitride regions of the second conductivity type comprises a first section laterally positioned between adjacent protrusions and a second section extending in a direction normal to the first side of the substrate. The MPS diode further includes a first metallic structure electrically coupled to one or more of the protrusions and to one or more of the second sections.

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: 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 and disposed adjacent to the drain along a vertical direction. The field effect transistor also includes a channel region comprising a third III-nitride material coupled to the drift region, a gate region at least partially surrounding the channel region, and a gate contact electrically coupled to the gate region. The field effect transistor further includes a source coupled to the channel region. The source includes a GaN-layer coupled to an InGaN layer. 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 field effect transistor is along the vertical direction.

Abstract: A method for fabricating an electronic device includes providing an engineered substrate structure comprising a III-nitride seed layer, forming GaN-based functional layers coupled to the III-nitride seed layer, and forming a first electrode structure electrically coupled to at least a portion of the GaN-based functional layers. The method also includes joining a carrier substrate opposing the GaN-based functional layers and removing at least a portion of the engineered substrate structure. The method further includes forming a second electrode structure electrically coupled to at least another portion of the GaN-based functional layers and removing the carrier substrate.