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 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:
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 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 high electron mobility transistor that includes a buried region, a channel layer overlying the buried region, a gate electrode, and a drain electrode overlying the buried region. The buried region can extend toward and does not underlie the gate electrode. In a particular aspect, the electronic device can further include a p-type semiconductor member overlying the channel layer. The gate electrode can overlie the channel layer, a p-type semiconductor member overlying the channel layer. The drain electrode can overlie and contact the buried region and the p-type semiconductor member. The p-type semiconductor member can be disposed between the gate and drain electrodes. In another embodiment, a source-side buried region may be used in addition to or in place of the buried region that is coupled to the drain electrode.
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:
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:
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:
In one embodiment, a high electron mobility device structure includes heterostructure with a Group III-nitride channel layer and a Group III-nitride barrier layer that forms a two-dimensional electron gas layer at an interface between the two layers. At least one current carrying electrode includes a recess-structured conductive contact adjoining and making Ohmic contact with the two-dimensional electron gas layer. The recess-structured conductive contact has at least one side surface defined to have a rounded wavy shape.
Abstract:
A HEMT semiconductor device can include a dielectric layer that includes a silicon nitride film and an AlN film. In an embodiment, the HEMT semiconductor device can include a GaN film and an AlGaN film. In a process of forming the HEMT device, the AlN can provide an etch stop when forming an opening for a gate electrode.