Abstract: A semiconductor device includes a III-nitride substrate and a channel structure coupled to the III-nitride substrate. The channel structure comprises a first III-nitride epitaxial material and is characterized by one or more channel sidewalls. The semiconductor device also includes a source region coupled to the channel structure. The source region comprises a second III-nitride epitaxial material. The semiconductor device further includes a III-nitride gate structure coupled to the one or more channel sidewalls, a gate metal structure in electrical contact with the III-nitride gate structure, and a dielectric layer overlying at least a portion of the gate metal structure. A top surface of the dielectric layer is substantially co-planar with a top surface of the source region.

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 III-nitride semiconductor device includes an active region for supporting current flow during forward-biased operation of the III-nitride semiconductor device. The active region includes a first III-nitride epitaxial material having a first conductivity type, and a second III-nitride epitaxial material having a second conductivity type. The III-nitride semiconductor device further includes an edge-termination region physically adjacent to the active region and including an implanted region comprising a portion of the first III-nitride epitaxial material. The implanted region of the first III-nitride epitaxial material has a reduced electrical conductivity in relation to portions of the first III-nitride epitaxial material adjacent to the implanted 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 semiconductor structure includes a GaN substrate having a first surface and a second surface opposing the first surface. The GaN substrate is characterized by a first conductivity type and a first dopant concentration. The semiconductor structure also includes a first GaN epitaxial layer of the first conductivity type coupled to the second surface of the GaN substrate and a second GaN epitaxial layer of a second conductivity type coupled to the first GaN epitaxial layer. The second GaN epitaxial layer includes an active device region, a first junction termination region characterized by an implantation region having a first implantation profile, and a second junction termination region characterized by an implantation region having a second implantation profile.

Abstract: A semiconductor device includes a III-nitride substrate and a first III-nitride epitaxial layer coupled to the III-nitride substrate and comprising a drift region, a channel region, and an extension region. The channel region is separated from the III-nitride substrate by the drift region. The channel region is characterized by a first width. The extension region is separated from the drift region by the channel region. The extension region is characterized by a second width less than the first width. The semiconductor device also includes a second III-nitride epitaxial layer coupled to a top surface of the extension region, a III-nitride gate structure coupled to a sidewall of the channel region and laterally self-aligned with respect to the extension region, and a gate metal structure in electrical contact with the III-nitride gate structure and laterally self-aligned with respect to the extension region.

Abstract: A semiconductor device includes a III-nitride substrate of a first conductivity type, a first III-nitride epitaxial layer of the first conductivity type coupled to the III-nitride substrate, and a first III-nitride epitaxial structure coupled to a first portion of a surface of the first III-nitride epitaxial layer. The first III-nitride epitaxial structure has a sidewall. The semiconductor device further includes a second III-nitride epitaxial structure of the first conductivity type coupled to the first III-nitride epitaxial structure, a second III-nitride epitaxial layer of the first conductivity type coupled to the sidewall of the second III-nitride epitaxial layer and a second portion of the surface of the first III-nitride epitaxial layer, and a third III-nitride epitaxial layer of a second conductivity type coupled to the second III-nitride epitaxial layer. The semiconductor device also includes one or more dielectric structures coupled to a surface of the third III-nitride epitaxial layer.

Abstract: An array of GaN-based vertical JFETs includes a GaN substrate comprising a drain of one or more of the JFETs and one or more epitaxial layers coupled to the GaN substrate. The array also includes a plurality of hexagonal cells coupled to the one or more epitaxial layers and extending in a direction normal to the GaN substrate. Sidewalls of the plurality of hexagonal cells are substantially aligned with respect to crystal planes of the GaN substrate. The array further includes a plurality of channel regions, each having a portion adjacent a sidewall of the plurality of hexagonal cells, a plurality of gate regions of one or more of the JFETs, each electrically coupled to one or more of the plurality of channel regions, and a plurality of source regions of one or more of the JFETs electrically coupled to one or more of the plurality of channel regions.

Abstract: An electronic package includes a leadframe, a plurality of pins, a gallium-nitride (GaN) transistor, and a GaN diode. The GaN transistor includes a drain region, a drift region, a source region, and a gate region; the drain region includes a GaN substrate and a drain contact, the drift region includes a first GaN epitaxial layer coupled to the GaN substrate, the source region includes a source contact and is separated from the GaN substrate by the drift region, and the gate region includes a second GaN epitaxial layer and a gate contact. The GaN diode includes an anode region and a cathode region, the cathode region including the GaN substrate and a cathode contact, and the anode region including a third GaN epitaxial layer coupled to the GaN substrate and an anode contact. The drain contact and the anode contact are electrically connected to the leadframe.

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: An example control element for use in a power supply includes a first terminal, a power MOSFET, and a control circuit. The power MOSFET has a drain terminal, a source terminal, a control terminal, and a tap terminal. In operation, a voltage at the tap terminal is less than and tracks a voltage at the drain terminal when the voltage at the drain terminal is less than a pinch off voltage of the power MOSFET. The control circuit includes a PWM circuit and a start-up circuit. The PWM circuit provides a control signal to the power MOSFET to switch the power MOSFET on and off in response to the feedback signal. The start-up circuit charges a bypass capacitor at the first terminal in response to the voltage at the tap terminal until a voltage at the first terminal reaches a first voltage level.

Abstract: A high-voltage transistor device comprises a spiral resistive field plate over a first well region between a drain region and a source region of the high-voltage transistor device, wherein the spiral resistive field plate is separated from the first well region by a first isolation layer, and is coupled between the drain region and the source region. The high-voltage transistor device further comprises a plurality of first field plates over the spiral resistive field plate with each first field plate covering one or more segments of the spiral resistive field plate, wherein the plurality of first field plates are isolated from the spiral resistive field plate by a first dielectric layer, and wherein the plurality of first field plates are isolated from each other, and a starting first field plate is connected to the source 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: The present technology is directed generally to a semiconductor device. In one embodiment, the semiconductor device includes a first vertical transistor and a second vertical transistor, and the first vertical transistor is stacked on top of the second vertical transistor. The first vertical transistor is mounted on a lead frame with the source electrode of the first vertical transistor coupled to the lead frame. The second vertical transistor is stacked on the first vertical transistor with the source electrode of the second vertical transistor coupled to the drain electrode of the first vertical transistor.

Abstract: A method for fabricating an edge termination, which can be used in conjunction with GaN-based materials, includes providing a substrate of a first conductivity type. The substrate has a first surface and a second surface. The method also includes 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 substrate, the first GaN epitaxial layer and the second GaN epitaxial layer can be referred to as an epitaxial structure.

Abstract: An embodiment of a vertical power device includes a III-nitride substrate, a drift region coupled to the III-nitride substrate and comprising a III-nitride material of a first conductivity type, and a channel region coupled to the drift region and comprising a III-nitride material of the first conductivity type. The vertical power device also includes a source region coupled to the channel region and comprising a III-nitride material of the first conductivity type, and a gate region coupled to the channel region. The gate region includes a III-nitride material of a second conductivity type. The vertical power device further includes a source-coupled region coupled to the drift region and electrically connected with the source region. The source-coupled region includes a III-nitride material of the second conductivity type.

Abstract: A semiconductor structure includes a GaN substrate having a first surface and a second surface opposing the first surface. The GaN substrate is characterized by a first conductivity type and a first dopant concentration. The semiconductor structure also includes a first GaN epitaxial layer of the first conductivity type coupled to the second surface of the GaN substrate and a second GaN epitaxial layer of a second conductivity type coupled to the first GaN epitaxial layer. The second GaN epitaxial layer includes an active device region, a first junction termination region characterized by an implantation region having a first implantation profile, and a second junction termination region characterized by an implantation region having a second implantation profile.

Abstract: A semiconductor device includes a III-nitride substrate and a first III-nitride epitaxial layer coupled to the III-nitride substrate and comprising a drift region, a channel region, and an extension region. The channel region is separated from the III-nitride substrate by the drift region. The channel region is characterized by a first width. The extension region is separated from the drift region by the channel region. The extension region is characterized by a second width less than the first width. The semiconductor device also includes a second III-nitride epitaxial layer coupled to a top surface of the extension region, a III-nitride gate structure coupled to a sidewall of the channel region and laterally self-aligned with respect to the extension region, and a gate metal structure in electrical contact with the III-nitride gate structure and laterally self-aligned with respect to the extension region.

Abstract: Vertical capacitive depletion field effect transistors (VCDFETs) and methods for fabricating VCDFETs are disclosed. An example VCDFET includes one or more interleaved drift and gate regions. The gate region(s) may be configured to capacitively deplete the drift region(s) though one or more insulators that separate the gate region(s) from the drift region(s). The drift region(s) may have graded/non-uniform doping profiles. In addition, one or more ohmic and/or Schottky contacts may be configured to couple one or more source electrodes to the drift region(s).

Abstract: A semiconductor structure includes a GaN substrate with a first surface and a second surface. The GaN substrate is characterized by a first conductivity type and a first dopant concentration. A first electrode is electrically coupled to the second surface of the GaN substrate. The semiconductor structure further includes a first GaN epitaxial layer of the first conductivity type coupled to the first surface of the GaN substrate and a second GaN layer of a second conductivity type coupled to the first GaN epitaxial layer. The first GaN epitaxial layer comprises a channel region. The second GaN epitaxial layer comprises a gate region and an edge termination structure. A second electrode coupled to the gate region and a third electrode coupled to the channel region are both disposed within the edge termination structure.