Abstract: High Electron Mobility Transistors (HEMTs) are described with a circular gate, with a drain region disposed within the circular gates and circular source region disposed around the circular gates. The circular gate and the circular source region may form complete circles.

Abstract: In a general aspect, a semiconductor device assembly includes a first portion of a semiconductor substrate; a second portion of the semiconductor substrate, and a semiconductor device layer disposed on the first portion of the semiconductor substrate and the second portion of the semiconductor substrate. The semiconductor device layer includes a first semiconductor device disposed on the first portion of the semiconductor substrate, and a second semiconductor device disposed on the second portion of the semiconductor substrate. The assembly also includes an isolation trench defined in the semiconductor substrate that has a dielectric material disposed therein. The isolation trench is disposed between the first portion of the semiconductor substrate and the second portion of the semiconductor substrate, and electrically isolates the first portion of the semiconductor substrate from the second portion of the semiconductor substrate. The semiconductor device layer excludes the isolation trench.

Abstract: In an embodiment, a HEMT is formed to have a main transistor having a main active area and a sense transistor having a sense active area. An embodiment may include that the main active area is isolated from the sense active area.

Abstract: A High Electron Mobility Transistor (HEMT) includes a source, a drain, a channel layer extending between the source and the drain, a barrier layer formed in contact with the channel layer, and extending between the source and the drain, and a gate formed in contact with, and covering at least a portion of, the barrier layer. The gate has gate edge portions and a gate central portion, and dielectric spacers may be formed over the gate edge portions, with the dielectric spacers having a first width therebetween proximal to the gate, and a second width therebetween distal from the gate, where the second width is longer than the first width.

Abstract: A process to form a HEMT can have a gate electrode layer that initially has a plurality of spaced-apart doped regions. In an embodiment, any of the spaced-apart doped regions can be formed by depositing or implanting p-type dopant atoms. After patterning, the gate electrode can include an n-type doped region over the p-type doped region. In another embodiment a barrier layer can underlie the gate electrode and include a lower film with a higher Al content and thinner than an upper film. In a further embodiment, a silicon nitride layer can be formed over the gate electrode layer and can help to provide Si atoms for the n-type doped region and increase a Mg:H ratio within the gate electrode. The HEMT can have good turn-on characteristics, low gate leakage when in the on-state, and better time-dependent breakdown as compared to a conventional HEMT.

Abstract: In a general aspect, a semiconductor device assembly can include a semiconductor substrate that excludes a buried oxide layer. The semiconductor device assembly can also include a first semiconductor device stack disposed on a first portion of the semiconductor substrate, and a second semiconductor device stack disposed on a second portion of the semiconductor substrate. The semiconductor device assembly can further include an isolation trench having a dielectric material disposed therein, the isolation trench being disposed between the first portion of the semiconductor substrate and the second portion of the semiconductor substrate. The isolation trench can electrically isolate the first portion of the semiconductor substrate from the second portion of the semiconductor substrate.

Abstract: An electronic device can include a HEMT. In an embodiment, a gate electrode, a drain electrode, and an access region including a first portion closer to the gate electrode and a second portion closer to the drain electrode. A lower dielectric film can overlie a portion of the access region, and an upper dielectric region can overlie another portion of the access region. In another embodiment, a dielectric film can have a relatively positive or negative charge and a varying thickness. In a further embodiment, the HEMT can include a gate electrode; a dielectric film overlying the gate electrode and defining openings to the gate electrode, wherein a portion of the dielectric film is disposed between the openings; and a gate interconnect extending into the openings of the dielectric film and contacting the gate electrode and the portion of the dielectric film.

Abstract: An electronic device including a transistor structure, and a process of forming the electronic device can include providing a workpiece including a substrate, a first layer, and a channel layer including a compound semiconductor material; and implanting a species into the workpiece such that the projected range extends at least into the channel and first layers, and the implant is performed into an area corresponding to at least a source region of the transistor structure. In an embodiment, the area corresponds to substantially all area occupied by the transistor structure. In another embodiment, the implant can form crystal defects within layers between the substrate and source, gate, and drain electrodes. The crystal defects may allow resistive coupling between the substrate and the channel structure within the transistor structure. The resistive coupling allows for better dynamic on-state resistance and potentially other electrical properties.

Abstract: An Enhancement Mode (e-mode) Metal Insulator Semiconductor (MIS) High Electron Mobility Transistor (HEMT), or EMISHEMT, with GaN channel regrowth under a gate area, is described. The EMISHEMT with GaN channel regrowth under a gate area provides a normally-off device with a suitably high and stable threshold voltage, while providing a low gate leakage current. A channel layer provides a 2DEG and associated low on-resistance, while a channel-material layer extends through an etched recess and into the channel layer, and disrupts the 2DEG locally to enable the normally-off operation.

Abstract: An opto-electronic High Electron Mobility Transistor (HEMT) may include a current channel including a two-dimensional electron gas (2DEG). The opto-electronic HEMT may further include a photoelectric bipolar transistor embedded within at least one of a source and a drain of the HEMT, the photoelectric bipolar transistor being in series with the current channel of the HEMT.

Abstract: An electronic device can include a HEMT. In an embodiment, a gate electrode, a drain electrode, and an access region including a first portion closer to the gate electrode and a second portion closer to the drain electrode. A lower dielectric film can overlie a portion of the access region, and an upper dielectric region can overlie another portion of the access region. In another embodiment, a dielectric film can have a relatively positive or negative charge and a varying thickness. In a further embodiment, the HEMT can include a gate electrode; a dielectric film overlying the gate electrode and defining openings to the gate electrode, wherein a portion of the dielectric film is disposed between the openings; and a gate interconnect extending into the openings of the dielectric film and contacting the gate electrode and the portion of the dielectric film.

Abstract: An electronic device can include a HEMT. In an embodiment, a gate electrode, a drain electrode, and an access region including a first portion closer to the gate electrode and a second portion closer to the drain electrode. A lower dielectric film can overlie a portion of the access region, and an upper dielectric region can overlie another portion of the access region. In another embodiment, a dielectric film can have a relatively positive or negative charge and a varying thickness. In a further embodiment, the HEMT can include a gate electrode; a dielectric film overlying the gate electrode and defining openings to the gate electrode, wherein a portion of the dielectric film is disposed between the openings; and a gate interconnect extending into the openings of the dielectric film and contacting the gate electrode and the portion of the dielectric film.

Abstract: An electronic device can include a HEMT. In an embodiment, a gate electrode, a drain electrode, and an access region including a first portion closer to the gate electrode and a second portion closer to the drain electrode. A lower dielectric film can overlie a portion of the access region, and an upper dielectric region can overlie another portion of the access region. In another embodiment, a dielectric film can have a relatively positive or negative charge and a varying thickness. In a further embodiment, the HEMT can include a gate electrode; a dielectric film overlying the gate electrode and defining openings to the gate electrode, wherein a portion of the dielectric film is disposed between the openings; and a gate interconnect extending into the openings of the dielectric film and contacting the gate electrode and the portion of the dielectric film.

Abstract: An electronic device can include a drain electrode of a high electron mobility transistor overlying a channel layer; a source electrode overlying the channel layer, wherein a lowermost portion of the source electrode overlies at least a portion of the channel layer; and a gate electrode of the high electron mobility transistor overlying the channel layer; and a current limiting control structure that controls current passing between the drain and source electrodes. The current limiting control structure can be disposed between the source and gate electrodes, the current limiting control structure can be coupled to the source electrode and the first high electron mobility transistor, and the current limiting control structure has a threshold voltage. The current limiting control structure can be a Schottky-gated HEMT or a MISHEMT.

Abstract: An electronic device can include a channel layer; an access region having an aluminum content substantially uniform or increasing with distance from the channel layer; and a gate dielectric layer overlying and contacting the channel layer. A process of forming an electronic device can include providing a substrate and a channel layer of a III-V semiconductor material over the substrate; forming a masking feature over the channel layer; and forming an access region over the channel layer. In an embodiment, the channel layer can include GaN, and the access region has an aluminum content that is substantially uniform or increases with distance from the channel layer. In another embodiment, the process can include removing at least a portion the masking feature and forming a gate dielectric layer over the channel layer. A dielectric film of the masking feature or the gate dielectric layer contacts the channel layer.

Abstract: An electronic device can include a HEMT that includes a channel layer, a barrier layer, and a gate electrode. The barrier layer can be disposed between the channel layer and the gate electrode and include a first portion, a second portion, and a third portion. The second portion can be spaced apart from the channel layer by the first portion, and the second portion is spaced apart from the gate electrode by the third portion. The second portion of the barrier layer can be configured to trap more charge, more readily recombine electrons and holes, or both as compared to each of the first and third portions of the barrier layer. The HEMT can have a VTH of at least 2 V and a subthreshold slope of at most 50 mV/decade of IDS.

Abstract: A process of forming an electronic device can include forming a channel layer overlying a substrate and forming a barrier layer overlying the channel layer. In an embodiment, the process can further include forming a p-type semiconductor layer over the barrier layer, patterning the p-type semiconductor layer to define at least part of a gate electrode of a transistor structure, and forming an access region layer over the barrier layer. In another embodiment, the process can further include forming an etch-stop layer over the barrier layer, forming a sacrificial layer over the etch-stop layer, patterning the etch-stop and sacrificial layers to define a gate region, forming an access region layer over the barrier layer after patterning the etch-stop and sacrificial layers, and forming a p-type semiconductor layer within the gate region.

Abstract: An electronic device including a transistor structure, and a process of forming the electronic device can include providing a workpiece including a substrate, a first layer, and a channel layer including a compound semiconductor material; and implanting a species into the workpiece such that the projected range extends at least into the channel and first layers, and the implant is performed into an area corresponding to at least a source region of the transistor structure. In an embodiment, the area corresponds to substantially all area occupied by the transistor structure. In another embodiment, the implant can form crystal defects within layers between the substrate and source, gate, and drain electrodes. The crystal defects may allow resistive coupling between the substrate and the channel structure within the transistor structure. The resistive coupling allows for better dynamic on-state resistance and potentially other electrical properties.

Abstract: An electronic device can include a channel layer, a first carrier supply layer, a gate electrode of a HEMT, and a drain electrode of the HEMT. The HEMT can have a 2DEG along an interface between the channel and first carrier supply layers. In an aspect, the 2DEG can have a highest density that is the highest at a point between the drain and gate electrodes. In another aspect, the HEMT can further comprise first and second carrier supply layers, wherein the first carrier supply layer is disposed between the channel and second carrier supply layers. The second carrier supply layer be thicker at a location between the drain and gate electrodes. In a further aspect, a process of forming an electronic device can include the HEMT. In a particular embodiment, first and second carrier supply layers can be epitaxially grown from an underlying layer.

Abstract: An electronic device can include a channel layer including AlzGa(1-z)N, where 0?z?0.1; a gate dielectric layer; and a gate electrode of a high electron mobility transistor (HEMT). The gate dielectric layer can be disposed between the channel layer and the gate electrode. The gate electrode includes a gate electrode film that contacts the gate dielectric layer, wherein the gate electrode film can include a material, wherein the material has a sum of an electron affinity and a bandgap energy of at least 6 eV. In some embodiments, the material can include a p-type semiconductor material. The particular material for the gate electrode film can be selected to achieve a desired threshold voltage for an enhancement-mode HEMT. In another embodiment, a portion of the barrier layer can be left intact under the gate structure. Such a configuration can improve carrier mobility and reduce Rdson.