The present disclosure presents a novel structure for a dielectric material for use with Group III-V material systems and a method of fabricating such a structure. More specifically, the present disclosure describes a novel dielectric layer that is formed on the top surface of a III-V material where the dielectric layer comprises a first region in contact with the top surface of the III-V material crystalline and a second region adjacent to the first region and at the upper side of the dielectric layer. The dielectric layer has material properties different from traditional dielectric layers as it is composed of both crystalline and amorphous structures. The crystalline structure is at the interface with the III-V material (such as AlGaN or GaN) but gradually transitions into an amorphous structure, both within the same layer and both comprising the same material.

An integrated circuit includes an NMOS transistor, a PMOS transistor and a vertical bipolar transistor. The vertical bipolar transistor has an intrinsic base with a band barrier at least 25 meV high at a surface boundary of the intrinsic base, except at an emitter-base junction with an emitter, and except at a base-collector junction with a collector. The intrinsic base may be laterally surrounded by an extrinsic base with a higher dopant density than the intrinsic base, wherein a higher dopant density provides the band barrier at lateral surfaces of the intrinsic base. A gate may be disposed on a gate dielectric layer over a top surface boundary of the intrinsic base adjacent to the emitter. The gate is configured to accumulate the intrinsic base immediately under the gate dielectric layer, providing the band barrier at the top surface boundary of the intrinsic base.

MOSHFET devices are provided, along with their methods of fabrication. The MOSHFET device can include a substrate; a multilayer stack on the substrate; a ultra-thin barrier layer on the multilayer stack, wherein the ultra-thin barrier layer has a thickness of about 0.5 nm to about 10 nm; a dielectric, discontinuous thin film layer on portions of the ultra-thin barrier layer, wherein the dielectric, discontinuous thin film layer comprises SiO.sub.2; a plurality of source electrodes and drain electrodes formed directly on the ultra-thin barrier layer in an alternating pattern such that the dielectric, discontinuous thin film layer is positioned between adjacent source electrodes and drain electrodes; a plurality of gate electrodes on the dielectric, discontinuous thin film layer; and a gate interconnect electrically connecting the plurality of gate electrodes.