Abstract: A layer of an amphoteric dopant on the surface of a group III-V intermetallic semiconductor crystal will diffuse into the crystal surface in a heating cycle forming a stable contact. The contact can be ohmic or rectifying depending on the localized presence of an excess of one crystal ingredient. A layer of Si on GaAs upon heating forms a rectifying contact. When the layer of Si contains As, the contact is ohmic.

Abstract: A method of manufacturing GaAs semiconductor devices includes the steps of emplacing doping impurities by ion implantation on at least one surface of a GaAs substrate, and a step of annealing to remove damage resulting from the implantation of the impurities in the GaAs material. Prior to the annealing, a silicon capping layer is deposited on the surface by either sputtering, evaporation, or vapor deposition to a thickness of 100-10,000 angstroms. Subsequent to the annealing, the silicon capping layer is removed by etching. The silicon cap prevents out-diffusion of arsenic from the GaAs, and has a coefficient of thermal expansion which is sufficiently close to that of the GaAs to inhibit the formation of cracks in the capping layer.

Abstract: Crystals of silicon carbide and aluminum nitride, substrates containing same, and the fabrication thereof.

Abstract: Crystals of silicon carbide and aluminum nitride, substrates containing same, and the fabrication thereof.

Abstract: Refractory oxide materials, for example, Al.sub.2 O.sub.3 (sapphire) and Al.sub.2 MgO.sub.4 (spinel) can be shaped to precise dimensions by using a preformed member having a higher melting temperature than the oxide in the outline of the desired shape placed in contact with the refractory oxide and subjecting the combination to a temperature between 1500.degree. C. and the melting temperature of the oxide in the presence of a forming gas atmosphere containing an inert gas and approximately 15% hydrogen. The refractory oxide is etched over the area of contact.

Abstract: Electronic grade aluminum nitride semiconductor material may be uniformly nucleated and epitaxially formed on an aluminum oxide substrate by reacting aluminum oxide or aluminum nitride with nitrogen in the presence of carbon.