Apparatus and circuits including transistors with different threshold voltages and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; an active layer that is formed over the substrate and comprises a plurality of active portions; a polarization modulation layer comprising a plurality of polarization modulation portions each of which is disposed on a corresponding one of the plurality of active portions; and a plurality of transistors each of which comprises a source region, a drain region, and a gate structure formed on a corresponding one of the plurality of polarization modulation portions. The transistors have at least three different threshold voltages.

Methods of manufacturing device assemblies, as well as associated semiconductor assemblies, devices, systems are disclosed herein. In one embodiment, a method of forming a semiconductor device assembly includes forming a semiconductor device assembly that includes a handle substrate, a semiconductor structure having a first side and a second side opposite the first side, and an intermediary material between the semiconductor structure and the handle substrate. The method also includes removing material from the semiconductor structure to form an opening extending from the first side of the semiconductor structure to at least the intermediary material at the second side of the semiconductor structure. The method further includes removing at least a portion of the intermediary material through the opening in the semiconductor structure to undercut the second side of the semiconductor structure.

A semiconductor body having a base carrier portion and a type III-nitride semiconductor portion is provided. The type III-nitride semiconductor portion includes a heterojunction and two-dimensional charge carrier gas. One or more ohmic contacts are formed in the type III-nitride semiconductor portion, the ohmic contacts forming an ohmic connection with the two-dimensional charge carrier gas. A gate structure is configured to control a conductive state of the two-dimensional charge carrier gas. Forming the one or more ohmic contacts comprises forming a structured laser-reflective mask on the upper surface of the type III-nitride semiconductor portion, implanting dopant atoms into the upper surface of the type III-nitride semiconductor portion, and performing a laser thermal anneal that activates the implanted dopant atoms.

A method for manufacturing nitride semiconductor device includes a second step of forming, on a gate layer material film, a gate electrode film that is a material film of a gate electrode, a third step of selectively etching the gate electrode film to form the gate electrode 22 of a ridge shape, and a fourth step of selectively etching the gate layer material film to form a semiconductor gate layer 21 of a ridge shape with the gate electrode 22 disposed at a width intermediate portion of a front surface thereof. The third step includes a first etching step for forming a first portion 22A from an upper end to a thickness direction intermediate portion of the gate electrode 22 and a second etching step being a step differing in etching condition from the first etching step and being for forming a remaining second portion 22B of the gate electrode.

A nitride semiconductor device includes a first nitride semiconductor layer, a second nitride semiconductor layer formed on the first nitride semiconductor layer, a third nitride semiconductor layer that is disposed on the second nitride semiconductor layer, has a ridge portion at least at a portion thereof, and contains an acceptor type impurity, a gate electrode that is disposed on the ridge portion, and a source electrode and a drain electrode that, on the second nitride semiconductor layer, are disposed across the ridge portion from each other, and has an active region and a nonactive region. The nonactive region has a first region and a film thickness of the second nitride semiconductor layer in the first region differs from a film thickness of the second nitride semiconductor layer in a region of the active region in which the ridge portion, the source electrode, and the drain electrode are not formed.

The present disclosure provides an integrated circuit structure of a group III nitride semiconductor, a manufacturing method thereof, and use thereof. The integrated circuit structure is a complementary circuit of HEMT and HHMT based on the group III nitride semiconductor, and can realize the integration of HEMT and HHMT on the same substrate, and the HEMT and the HHMT respectively have a polarized junction with a vertical interface, the crystal orientations of the polarized junctions of the HEMT and the HHMT are different, the two-dimensional carrier gas forms a carrier channel in a direction parallel to the polarized junction, and corresponding channel carriers are almost depleted by burying the doped region. Compared with the conventional silicon-based CMOS, the integrated circuit structure of the present disclosure have advantages in aspects of carrier mobility, on-state current density, switching speed and so on, can realize low on-resistance, low parasitic inductance, and normally-off state of the device, and can achieve the technical effects of higher on-state current density, higher integration degree, and lower energy consumption.

The structure and technology to improve the device performance of III-nitride semiconductor transistors at high drain voltage when the device is off is disclosed. P-type semiconductor regions are disposed between the gate electrode and the drain contact of the transistor structure. The P-type regions are electrically connected to the drain electrode. In some embodiments, the P-type regions are physically contacting the drain contact. In other embodiments, the P-type regions are physically separate from the drain contact, but electrically connected to the drain contact.

A high-electron mobility transistor includes a substrate; a channel layer on the substrate; a AlGaN layer on the channel layer; and a P—GaN gate on the AlGaN layer. The AlGaN layer comprises a first region and a second region. The first region has a composition that is different from that of the second region.

A semiconductor device includes an enhancement mode high electron mobility transistor (HEMT) with an active region and an isolation region. The HEMT includes a substrate, a group III-V body layer, a group III-V barrier layer, recesses, a passivation layer and an etch mask layer. The group III-V body layer is disposed on the substrate. The group III-V barrier layer is disposed on the group III-V body layer in the active region and the isolation region. The recesses are disposed in the group III-V barrier layer in the active region and the isolation region, respectively. The passivation layer disposed in the recesses of the active region and the isolation region. The etch mask layer disposed between the passivation layer and the group III-V barrier layer in the active region, where the etch mask layer is spaced apart from bottoms of the recesses in the active region and the isolation region.

A device including a III-N material is described. The device includes a transistor structure having a first layer including a first group III-nitride (III-N) material, a polarization charge inducing layer above the first layer, the polarization charge inducing layer including a second III-N material, a gate electrode above the polarization charge inducing layer and a source structure and a drain structure on opposite sides of the gate electrode. The device further includes a plurality of peripheral structures adjacent to transistor structure, where each of the peripheral structure includes the first layer, but lacks the polarization charge inducing layer, an insulating layer above the peripheral structure and the transistor structure, wherein the insulating layer includes a first dielectric material. A metallization structure, above the peripheral structure, is coupled to the transistor structure.