A support substrate is bonded to a GaN epitaxial substrate including at least an electron transport layer and an electron supply layer grown on a growth substrate in the Ga-polar direction such that the support substrate faces the Ga-plane of the GaN epitaxial substrate. Furthermore, at least the growth substrate is removed from the GaN epitaxial substrate so as to expose an N-plane of the GaN epitaxial substrate. Subsequently, a semiconductor element is formed on the N-plane side.

A GaN epitaxial substrate comprises a growth substrate and a multilayer structure grown on the growth substrate in the Ga-polar direction. The multilayer structure comprises: a buffer layer, an n-type conductive layer formed on the buffer layer, a first GaN layer formed on the n-type conductive layer, an electron supply layer formed on the first GaN layer, and a second GaN layer formed on the electron supply layer.

Semiconductor devices and fin field effect transistors (FinFETs) are disclosed. In some embodiments, a representative semiconductor device includes a group III material over a substrate, the group III material comprising a thickness of about 2 monolayers or less, and a group III-V material over the group III material.

In order to reduce costs as well as to effectively dissipate heat in certain RF circuits, a semiconductor device of the circuit can include one or more active devices such as transistors, diodes, and/or varactors formed of a first semiconductor material system integrated onto (e.g., bonded to) a base substrate formed of a second semiconductor material system that includes other circuit components. The first semiconductor material system can, for example, be the III-V or III-N semiconductor system, and the second semiconductor material system can, for example be silicon.

Fabricating a crystalline metal-phosphide layer may include providing a crystalline base substrate and a step of forming a crystalline metal-source layer. The method may further include performing a chemical conversion reaction to convert the metal-source layer to the crystalline metal phosphide layer. One or more corresponding semiconductor structures can be also provided.

A III-N device is described with a III-N material layer, an insulator layer on a surface of the III-N material layer, an etch stop layer on an opposite side of the insulator layer from the III-N material layer, and an electrode defining layer on an opposite side of the etch stop layer from the insulator layer. A recess is formed in the electrode defining layer. An electrode is formed in the recess. The insulator can have a precisely controlled thickness, particularly between the electrode and III-N material layer.

A method of fabricating high electron mobility transistor, including the steps of providing a substrate with active areas, forming a buffer layer, a channel layer and a barrier layer sequentially on the substrate and gate, source and drain on the barrier layer, forming a trench surrounding the channel layer and the barrier layer, and forming a trench isolation structure in the trench, wherein the trench isolation structure applies stress on the channel layer and the barrier layer and modify two-dimension electron gas (2DEG) or two-dimension hole gas (2DHG) of the high electron mobility transistor.

Methods and structures includes providing a substrate, forming a prelayer over a substrate, forming a barrier layer over the prelayer, and forming a channel layer over the barrier layer. Forming the prelayer may include growing the prelayer at a graded temperature. Forming the barrier layer is such that the barrier layer may include GaAs or InGaAs. Forming the channel layer is such that the channel layer may include InAs or an Sb-based heterostructure. Thereby structures are formed.

Techniques and methods related to strained NMOS and PMOS devices without relaxed substrates, systems incorporating such semiconductor devices, and methods therefor may include a semiconductor device that may have both n-type and p-type semiconductor bodies. Both types of semiconductor bodies may be formed from an initially strained semiconductor material such as silicon germanium. A silicon cladding layer may then be provided at least over or on the n-type semiconductor body. In one example, a lower portion of the semiconductor bodies is formed by a Si extension of the wafer or substrate. By one approach, an upper portion of the semiconductor bodies, formed of the strained SiGe, may be formed by blanket depositing the strained SiGe layer on the Si wafer, and then etching through the SiGe layer and into the Si wafer to form the semiconductor bodies or fins with the lower and upper portions.

Incorporation of metallic quantum dots (e.g., silver bromide (AgBr) films) into the source and drain regions of a MOSFET can assist in controlling the transistor performance by tuning the threshold voltage. If the silver bromide film is rich in bromine atoms, anion quantum dots are deposited, and the AgBr energy gap is altered so as to increase V.sub.t. If the silver bromide film is rich in silver atoms, cation quantum dots are deposited, and the AgBr energy gap is altered so as to decrease V.sub.t. Atomic layer deposition (ALD) of neutral quantum dots of different sizes also varies V.sub.t. Use of a mass spectrometer during film deposition can assist in varying the composition of the quantum dot film. The metallic quantum dots can be incorporated into ion-doped source and drain regions. Alternatively, the metallic quantum dots can be incorporated into epitaxially doped source and drain regions.