Semiconductor Schottky devices having improved voltage blocking characteristics

Claim 1

A semiconductor device comprising a semiconductor body having a body portion of a first conductivity type, a metal-based layer at a surface of the body and forming an active Schottky barrier with said body portion at a plurality of separate areas, and a plurality of closely-spaced field-relief regions of a second, opposite conductivity type at said surface of the body and extending only partly through said body portion, each of which field-relief regions forms with the body portion a p-n junction which extends to a depth in the body below that of the active Schottky barrier, the separate areas of the active Schottky barrier being located between the closely-spaced field-relief regions, the closely-spaced field-relief regions being distributed throughout the width of said active Schottky barrier and being contacted at said surface by the metal-based layer and being sufficiently closely spaced such that in operation depletion layers extending in the body portion from neighboring field-relief regions merge together under reverse-bias of the active Schottky barrier, and means for establishing a sufficiently low conductivity-type determining dopant concentration of the field-relief regions of less than about 5×10 16 cm -3 at the surface where contacted by the metal-based layer to form with the metal-based layer a further Schottky barrier which is in series with the p-n junction between the field-relief regions and the body portion, thus restricting the flow of minority carriers into the body portion under forward-bias of the active Schottky barrier.