Abstract: A double heterojunction bipolar transistor includes diamond as the semiconductor material for the collector and emitter, while silicon carbide provides the base. Accordingly, the diamond is readily and reproducibly p-doped, and the silicon carbide may be fabricated by a solid state reaction to form an n-type intrinsic semiconductor. The base is preferably not so thick as to greatly increase transit time, yet sufficiently thick to prevent tunneling. In one embodiment single crystal diamond and single crystal silicon carbide are used in direct contact with each other. In another embodiment of the transistor, polycrystalline diamond is used, and a layer of insulating diamond is positioned between each face of the silicon carbide layer and the diamond layers. A method for fabricating the transistor includes depositing silicon on the diamond and annealing same so as to produce silicon carbide by a solid state reaction. The silicon carbide so produced is intrinsically n-type.

Abstract: An insulated gate field-effect transistor including an active diamond layer having a desired boron doping concentration profile. The boron doping concentration profile generally decreases with increasing depth into the diamond layer so that the active channel has a doping sufficient for field-effect transistor operation. An insulated gate electrode is formed on the highly doped surface and provides a low gate leakage current and passivates the surface of the diamond layer.

Abstract: A semiconductor device comprising a semiconducting diamond layer, (e.g. single crystal or polycrystalline), a refractory metal silicide layer adjacent the diamond layer for forming a rectifying contact therewith, and an annealed interface region between the diamond layer and the refractory metal silicide layer. The annealed interface region is preferably a non-abrupt interface comprising material selected from the group consisting of silicon carbide, the carbide of the refractory metal and mixtures thereof. The present invention also provides a method for making a rectifying contact on a semiconducting diamond layer comprising the steps of forming a refractory metal silicide on the diamond layer, and annealing the refractory metal silicide and diamond layer. Preferably, the step of annealing comprises the step of heating the diamond layer and refractory metal silicide at temperature of at least about 450.degree. C.