Abstract: A semiconductor die includes a semiconductor body, and a multi-layer environmental barrier on the semiconductor body. The multi-layer environmental barrier includes first and second sublayers of first and second oxide materials, respectively, where the first oxide material is different than the second oxide material. Related devices and fabrication methods are also discussed.

Abstract: A transistor device ac includes a semiconductor epitaxial layer structure including a channel layer and a barrier layer on the channel layer, wherein the barrier layer has a higher bandgap than the channel layer, a source contact and a drain contact on the barrier layer, and a gate contact on the barrier layer between source contact and the drain contact. The device further includes a plurality of selective modified access regions at an upper surface of the barrier layer opposite the channel layer. The selective modified access regions include a material having a lower surface barrier height than the barrier layer, and the plurality of selective modified access regions are spaced apart on the barrier layer along a length of the gate contact.

Abstract: Field reducing structures for transistor devices having Group III-nitride semiconductor structures are provided. In one example, a transistor device includes a nitrogen-polar (N-polar) Group III-nitride semiconductor structure. The transistor device includes a source contact, a drain contact, and a gate contact. The transistor device includes a field reducing structure operable to reduce an electric field in a region in the N-polar Group III-nitride semiconductor structure between the gate contact and the drain contact.

Abstract: RF transistor amplifiers include an RF transistor amplifier die having a Group III nitride-based semiconductor layer structure and a plurality of gate terminals, a plurality of drain terminals, and at least one source terminal that are each on an upper surface of the semiconductor layer structure, an interconnect structure on an upper surface of the RF transistor amplifier die, and a coupling element between the RF transistor amplifier die and the interconnect structure that electrically connects the gate terminals, the drain terminals and the source terminal to the interconnect structure.

Abstract: A transistor amplifier includes a die comprising a gate terminal, a drain terminal, and a source terminal, a circuitry module on the transistor die and electrically coupled to the gate terminal, the drain terminal, and/or the source terminal, and one or more passive electrical components on a first surface of the circuitry module. The one or more passive electrical components are electrically coupled between the gate terminal and a first lead of the transistor amplifier and/or between the drain terminal and a second lead of the transistor amplifier.

Abstract: A transistor device includes a metal submount; a transistor die arranged on said metal submount; at least one integrated passive device (IPD) component that includes a substrate arranged on said metal submount; and one or more interconnects extending between the transistor die and the at least one integrated passive device (IPD) component. The substrate includes a silicon carbide (SiC) substrate.

Abstract: Group-III-nitride high-electron-mobility transistors (HEMTs) are provided. A Group-III-nitride HEMT includes a substrate. The Group-III-nitride HEMT includes a barrier layer on the substrate. The Group-III-nitride HEMT includes a source contact and a drain contact that are on the barrier layer. Moreover, the Group-III-nitride HEMT includes a Group-III-nitride capping layer on the barrier layer and separated from the drain contact by a gap.

Abstract: A high electron mobility transistor comprises a semiconductor layer structure that includes a channel layer and a barrier layer and source and drain contacts on the semiconductor layer structure. A gate contact and a multi-layer passivation structure are provided on the semiconductor layer structure between the source contact and the drain contact. The multi-layer passivation structure comprises at least first and second silicon nitride layers that have different material compositions. A spacer passivation layer is provided on sidewalls of the first and second silicon nitride layers. A material composition of the spacer passivation layer is different than a material composition of at least one of the layers of the multi-layer passivation structure.

Abstract: A transistor device includes a metal submount; a transistor die arranged on said metal submount; at least one integrated passive device (IPD) component that includes a substrate arranged on said metal submount; and one or more interconnects extending between the transistor die and the at least one integrated passive device (IPD) component. The substrate includes a silicon carbide (SiC) substrate.

Abstract: A transistor device according to some embodiments includes a channel layer, a barrier layer on the channel layer, and source and drain contacts on the barrier layer, and a gate contact on the barrier layer between the source and drain contacts. The channel layer includes a sub-layer having an increased doping concentration level relative to a remaining portion of the channel layer. The presence of the sub-layer may reduce drain lag without substantially increasing gate lag.

Abstract: A device includes a substrate, a channel layer on the substrate, a barrier layer on the channel layer, a source electrically coupled to the barrier layer and/or the channel layer, a gate at least partially on the barrier layer, and a drain electrically coupled to the barrier layer and/or the channel layer. The device moreover includes a cap layer structured, configured, and/or arranged under an edge of the gate at a drain side.

Abstract: A semiconductor device is provided. The semiconductor device includes a semiconductor structure comprising silicon carbide. The semiconductor device further includes a mesa structure protruding in a first direction from the semiconductor structure, the mesa structure extending in a second direction between a first contact on the semiconductor structure and a second contact on the semiconductor structure. The semiconductor device further includes a channel region in the mesa structure. The semiconductor device further includes an electrically floating confining region, the electrically floating confining region in contact with the channel region in the mesa structure. The semiconductor device further includes a third contact on at least one sidewall of the mesa structure.

Abstract: Semiconductor structures including N-polar Group III-nitride are provided. The semiconductor structure includes an anti-reflective layer provided on an N-polar Group III-nitride semiconductor structure. The semiconductor structure includes a photoresist layer on the N-Polar Group III-nitride semiconductor structure. The anti-reflective layer has a thickness outside of an anti-reflectivity range associated with a photolithography process.

Abstract: A transistor includes a group III-Nitride channel layer; a group III-Nitride barrier layer on the group III-Nitride channel layer, the group III-Nitride barrier layer having a higher bandgap than a bandgap of the group III-Nitride channel layer; a low resistance contact layer on the group III-Nitride barrier layer and/or on the group III-Nitride channel layer; a source electrically coupled to the group III-Nitride barrier layer. A drain electrically coupled to the group III-Nitride barrier layer; and a gate on the group III-Nitride barrier layer. Additionally, at least one of the drain and the source are arranged on the low resistance contact layer.

Abstract: A transistor device according to some embodiments includes a semiconductor barrier layer, a surface dielectric layer on the semiconductor barrier layer, and a gate on the surface dielectric layer. The surface dielectric layer includes an aperture therein that is laterally spaced apart from the gate. The device includes an interlayer dielectric layer on the surface dielectric layer that extends over the gate and into the aperture in the surface dielectric layer, and a multiple-stepped field plate on the interlayer dielectric layer. The multiple-stepped field plate is laterally spaced apart from the gate. A recessed portion of the multiple-stepped field plate is above the aperture in the surface dielectric layer, and the multiple-stepped field plate includes a first step adjacent the recessed portion of the field plate on a side of the field plate opposite the gate, and a second step adjacent the first step.

Abstract: A HEMT transistor has a semiconductor layer structure that comprises a Group III nitride-based channel layer and a higher bandgap Group III nitride-based barrier layer on the channel layer. A gate finger and first and second source/drain contacts are provided on the semiconductor layer structure. A first source/drain region is provided in the semiconductor layer structure that includes a first implanted region that is underneath the first source/drain contact and a first auxiliary implanted region. A depth of the first implanted region is at least twice a depth of the first auxiliary implanted a region. The first source/drain region extends inwardly a first distance from a lower edge of an inner sidewall of the first source/drain contact, and extends outwardly a second smaller distance from a lower edge of an outer sidewall of the first source/drain contact.

Abstract: Semiconductor devices are provided that include a Group III nitride-based semiconductor layer structure. A first metal layer is formed on an upper surface of the semiconductor layer structure, a first dielectric layer is formed on an upper surface of the first metal layer, and a second metal layer is formed on an upper surface of the first dielectric layer. The first metal layer, the first dielectric layer and the second metal layer form a first capacitor. A second dielectric layer is formed on an upper surface of the second metal layer, a third dielectric layer is formed on an upper surface of the second dielectric layer, and a third metal layer is formed on upper surfaces of the second and third dielectric layers. The second metal layer, the second dielectric layer and the third metal layer form a second capacitor that is stacked on the first capacitor.

Abstract: Semiconductor devices are provided. In one example, a semiconductor device includes a Group III-nitride semiconductor structure. The semiconductor device includes a first contact on the Group III-nitride semiconductor structure. The semiconductor device includes a second contact on the Group III-nitride semiconductor structure. The second contact is spaced apart from the first contact. The Group III-nitride semiconductor structure includes a plurality of channel structures extending in a length direction between the first contact and the second contact. The semiconductor device includes an isolation implant region extending along at least a portion of a length of at least one of the plurality of channel structures. The isolation implant region comprises implanted dopants.

Abstract: A thermally conductive interposer includes an interposer substrate having a first substrate surface and a second substrate surface. The first substrate surface being configured to be attached to a first device component. The second substrate surface being configured to be attached to a second device component. The interposer substrate being configured to support the second device component on the first device component and integrate the first device component and the second device component within a microelectronic device. Further, the interposer substrate is configured to transfer heat between the first device component and the second device component; and the interposer substrate is configured to be electrically nonconductive.

Abstract: Semiconductor devices are provided. In one example, a semiconductor device includes a Group III-nitride semiconductor structure. The semiconductor device may include a gate contact on the Group III-nitride semiconductor structure. The semiconductor device may include a field plate overlapping the Group III-nitride semiconductor structure. The semiconductor device may include a thermally conductive passivation layer overlapping the gate contact. The thermally conductive passivation layer may be between the field plate and the Group III-nitride semiconductor structure. The thermally conductive passivation layer may contact the Group III-nitride semiconductor structure. The thermally conductive passivation layer may have a thermal conductivity of at least about 80 W/(m·k).