Structures for a bidirectional switch and methods of forming such structures. A substrate contact is formed in a trench defined in a substrate. A substrate includes a trench and a substrate contact in the trench. A bidirectional switch, which is on the substrate, includes a first source/drain electrode, a second source/drain electrode, an extension region between the first source/drain electrode and the second source/drain electrode, and a gate structure. A substrate-bias switch, which is on the substrate, includes a gate structure, a first source/drain electrode coupled to the substrate contact, a second source/drain electrode coupled to the first source/drain electrode of the bidirectional switch, and an extension region laterally between the gate structure and the first source/drain electrode.

A method is provided for forming Group IIIA-nitride layers, such as GaN, on substrates. The Group IIIA-nitride layers may be deposited on mesa-patterned semiconductor-on-insulator (SOI, e.g., silicon-on-insulator) substrates. The Group IIIA-nitride layers may be deposited by heteroepitaxial deposition on mesa-patterned semiconductor-on-insulator (SOI, e.g., silicon-on-insulator) substrates.

A semiconductor component includes a support having a lead integrally formed thereto. An insulated metal substrate is mounted to a surface of the support and a semiconductor chip is mounted to the insulated metal substrate. A III-N based semiconductor chip is mounted to the insulated metal substrate, where the III-N based semiconductor chip has a gate bond pad, a drain bond pad, and a source bond pad. A silicon based semiconductor chip is mounted to the III-N based semiconductor chip. In accordance with an embodiment the silicon based semiconductor chip includes a device having a gate bond pad, a drain bond pad, and a source bond pad. The drain bond pad of the III-N based semiconductor chip may be bonded to the substrate or to a lead. In accordance with another embodiment, the silicon based semiconductor chip is a diode.

Aspects of the present disclosure are directed to circuitry operable with enhanced capacitance and mitigation of avalanche breakdown. As may be implemented in accordance with one or more embodiments, an apparatus and/or method involves respective transistors of a cascode circuit, one of which controls the other in an off state by applying a voltage to a gate thereof. A plurality of doped regions are separated by trenches, with the conductive trenches being configured and arranged with the doped regions to provide capacitance across the source and the drain of the second transistor, and restricting voltage at one of the source and the drain of the second transistor, therein mitigating avalanche breakdown of the second transistor.

A semiconductor device having a voltage resistant structure in a first aspect of the present invention is provided, comprising a semiconductor substrate, a semiconductor layer on the semiconductor substrate, a front surface electrode above the semiconductor layer, a rear surface electrode below the semiconductor substrate, an extension section provided to a side surface of the semiconductor substrate, and a resistance section electrically connected to the front surface electrode and the rear surface electrode. The extension section may have a lower permittivity than the semiconductor substrate. The resistance section may be provided to at least one of the upper surface and the side surface of the extension section.

A layer structure for a normally-off transistor has an electron-supply layer made of a group-III-nitride material, a back-barrier layer made of a group-III-nitride material, a channel layer between the electron-supply layer and the back-barrier layer, made of a group-III-nitride material having a band-gap energy that is lower than the band-gap energies of the other layer mentioned. The material of the back-barrier layer is of p-type conductivity, while the material of the electron-supply layer and the material of the channel layer are not of p-type conductivity, the band-gap energy of the electron-supply layer is smaller than the band-gap energy of the back-barrier layer. In absence of an external voltage a lower conduction-band-edge of the third group-III-nitride material in the channel layer is higher in energy than a Fermi level of the material in the channel layer.

A semiconductor structure (100) comprising: a substrate (102), a first layer (106) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N disposed on the substrate, stacks (107, 109) of several second and third layers (108, 110) alternating against each other, between the substrate and the first layer, a fourth layer (112) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N, between the stacks, a relaxation layer of AlN disposed between the fourth layer and one of the stacks, and, in each of the stacks: the level of Ga of the second layers increases from one layer to the next in a direction from the substrate to the first layer, the level of Ga of the third layers is constant or decreasing from one layer to the next in said direction, the average mesh parameter of each group of adjacent second and third layers increasing from one group to the next in said direction, the thickness of the second and third layers is less than 5 nm.

The invention relates to a method for producing a semiconductor structure, characterised in that the method comprises a step (201) of depositing a crystalline passivation layer continuously covering the entire surface of a layer based on group III nitrides, said crystalline passivation layer, which is deposited from a precursor containing silicon atoms and a flow of nitrogen atoms, consisting of silicon atoms bound to the surface of the layer based on group III nitrides and arranged in a periodical arrangement such that a diffraction image of said crystalline passivation layer obtained by grazing-incidence diffraction of electrons in the direction [1-100] comprises: two fractional order diffraction lines (0, −⅓) and (0, −⅔) between the central line (0, 0) and the integer order line (0, −1), and two fractional order diffraction lines (0, ⅓) and (0, ⅔) between the central line (0, 0) and the integer order line (0, 1).

Multiple wide bandgap semiconductor wafers, each having active circuitry and an epitaxially formed backside drain contact layer, may be constructed from a single bulk semiconductor substrate by: forming foundational layers on the top of the bulk substrate via epitaxy; forming active circuitry atop the foundational layers; laser treating the backside of the bulk substrate to create a cleave line in one of the foundational layers; and exfoliating a semiconductor wafer from the bulk substrate, where the exfoliated semiconductor wafer contains the active circuits and at least a portion of the foundational layers. Wafers containing the foundational layers without complete active devices may be produced in a similar manner. The foundational layers may comprise a drain contact layer and a drift layer, and may additionally include a buffer layer between the drain contact layer and the drift layer.

A semiconductor device and a process of forming the semiconductor device are disclosed. The semiconductor device type of a high electron mobility transistor (HEMT) has double SiN films on a semiconductor layer, where the first SiN film is formed by the lower pressure chemical vapor deposition (LPCVD) technique, while, the second SiN film is deposited by the plasma assisted CVD (p-CVD) technique. Moreover, the gate electrode has an arrangement of double metals, one of which contains nickel (Ni) as a Schottky metal, while the other is free from Ni and covers the former metal. A feature of the invention is that the first metal is in contact with the semiconductor layer but apart from the second SiN film.