Abstract: A mask and encapsulating layer suitable for use on gallium arsenide substrates is described incorporating a layer of germanium selenide which is photosensitive and may be exposed and developed to form a mask suitable for ion implantation and which may also remain as a capping layer during an anneal process of ion implanted regions in a controlled atmosphere and temperature furnace wherein the layer of germanium selenide is converted to germanium which may subsequently be removed from the gallium arsenide substrate after the step of annealing.

Abstract: A self-aligned gate field effect transistor is described which is capable of operating at high frequencies. A method for making the transistor is described which comprises plating metal partially over an oxide layer, then removing the oxide to produce an overlapping metal portion and then plating again to produce a gate contact between the overlapping metal portions.

Abstract: A semiconductor device and particularly a self-aligned Schottky barrier gate field-effect transistor is made by epitaxial growth of facets corresponding to the source and drain regions on a surface of a semiconductor body through spaced apart preferably elongated windows in a masking layer and overgrowing edge portions of the masking layer at the windows to form overgrown portions on the facets. The channel region of the transistor is previously formed in the semiconductor body, preferably by epitaxial growth of a layer on a surface of a semiconductor body having a semi-insulating layer adjoining the surface. After removal of the masking layer, the Schottky barrier gate is self-aligned by deposition of metal on the unshielded portions of the planar surface between the facets.