An N-polar III-N high-electron mobility transistor device can include a III-N channel layer over an N-face of a III-N backbarrier, wherein a compositional difference between the channel layer and the backbarrier causes a 2DEG channel to be induced in the III-N channel layer adjacent to the interface between the III-N channel layer and the backbarrier. The device can further include a p-type III-N layer over the III-N channel layer and a thick III-N cap layer over the p-type III-N layer. The III-N cap layer can cause an increase in the charge density of the 2DEG channel directly below the cap layer, and the p-type III-N layer can serve to prevent a parasitic 2DEG from forming in the III-N cap layer.

A semiconductor device includes: a gate electrode including a junction portion forming a Schottky junction with a barrier layer; a projecting portion including first and second gate field plates and projecting from the junction portion; and an insulating layer including first and second sidewalls. An angle formed between a highest position of a bottom surface of the first gate field plate and a main surface of a substrate, viewed from the first position, is a second elevation angle. An angle formed between an end on the drain electrode side of a lowest portion of a bottom surface of the second gate field plate and the main surface, viewed from the first position, is a third elevation angle. The second elevation angle is larger than the third elevation angle. The bottom surface of the second gate field plate includes an inclined surface where a distance from the barrier layer monotonically increases.

A method for manufacturing a HEMT device includes forming, on a heterostructure, a dielectric layer, forming a through opening through the dielectric layer, and forming a gate electrode in the through opening. Forming the gate electrode includes forming a sacrificial structure, depositing by evaporation a first gate metal layer layer, carrying out a lift-off of the sacrificial structure, depositing a second gate metal layer by sputtering, and depositing a third gate metal layer. The second gate metal layer layer forms a barrier against the diffusion of metal atoms towards the heterostructure.

In some examples, a transistor comprises a gallium nitride (GaN) layer; a GaN-based alloy layer having a top side and disposed on the GaN layer, wherein source, drain, and gate contact structures are supported by the GaN layer; and a first doped region positioned in a drain access region and extending from the top side into the GaN layer.

A nitride-based semiconductor device includes a substrate, a buffer, a first nitride-based semiconductor layer, a second nitride-based semiconductor layer, a S/D electrode, a second S/D electrode, and a gate electrode. The buffer is disposed over the substrate and includes at least one layer of a nitride-based semiconductor compound doped with an acceptor at a top-most portion of the buffer. The first and second nitride-based semiconductor layers are disposed over the buffer. The first S/D electrode is disposed over the second nitride-based semiconductor layer, in which the first S/D electrode extends downward to a position lower than the first nitride-based semiconductor layer, so as to form at least one first interface with the top-most portion of the buffer, making contact with the at least one layer of the nitride-based semiconductor compound. The second S/D electrode and the gate electrode are disposed over the second nitride-based semiconductor layer.

Semiconductor device structures and methods for manufacturing the same are provided. The semiconductor device structure includes a substrate, a first nitride semiconductor layer, a second nitride semiconductor layer, a gate electrode, a first electrode, a first via and a second via. The substrate has a first surface and a second surface. The first nitride semiconductor layer is disposed on the first surface of the substrate. The second nitride semiconductor layer is disposed on the first nitride semiconductor layer and has a bandgap exceeding that of the first nitride semiconductor layer. The gate electrode and the first electrode are disposed on the second nitride semiconductor layer. The first via extends from the second surface and is electrically connected to the first electrode. The second via extends from the second surface. The depth of the first via is different from the depth of the second via.

A semiconductor device for power amplification includes: a source electrode, a drain electrode, and a gate electrode disposed above a semiconductor stack structure including a first nitride semiconductor layer and a second nitride semiconductor layer; and a source field plate that is disposed above the semiconductor stack structure between the gate electrode and the drain electrode, and has a same potential as a potential of the source electrode. The source field plate has a staircase shape, and even when length LF2 of an upper section is increased for electric field relaxation, an increase in parasitic capacitance Cds generated between the source field plate and a 2DEG surface is inhibited.

A method of manufacturing a high-electron-mobility transistor device is provided. The method includes sequentially forming a transition layer and a semiconductor layer on a substrate, etching a portion of a surface of the semiconductor layer to form a barrier layer region having a certain depth and forming a barrier layer in the barrier layer region, forming a source electrode and a drain electrode on a 2-dimensional electron gas (2-DEG) layer upward exposed at a surface of the semiconductor layer, in defining the 2-DEG layer formed along an interface between the semiconductor layer and the barrier layer, forming a passivation layer on the semiconductor layer, the barrier layer, the source electrode, and the drain electrode and etching a portion of the passivation layer to upward expose the source electrode, the drain electrode, and the barrier layer, and forming a gate electrode on the upward exposed barrier layer.

Embedded die packaging for high voltage, high temperature operation of power semiconductor devices is disclosed, wherein a power semiconductor die is embedded in package body comprising dielectric layers and electrically conductive layers, and where an external dielectric coating, such as a solder resist coating is provided on one or both external sides of the package body. The solder resist coating is patterned to avoid inside corners, e.g. the solder resist does not extend around or between electrical contact areas and thermal pads. It is observed that in conventional solder resist coatings, during thermal cycling, cracks tend to initiate at high stress points, such as at sharp inside corners. A solder resist layout which omits inside corners, and comprises outside corners only, is demonstrated to provide significantly improved resistance to initiation and propagation of cracks. Where inside corners are unavoidable, they are appropriately radiused to reduce stress.

A semiconductor device according to one embodiment of the present disclosure includes a low resistance material section and a low thermal resistance material section. The low resistance material section is in contact with a barrier layer, a channel layer, and a source electrode or a drain electrode, and includes a low resistance material having a lower resistance than the channel layer. The low thermal resistance material section is in contact with the channel layer and the buffer layer, and includes a low thermal resistance material having a lower thermal resistance than the channel layer.