Semiconductor devices

A semiconductor device comprising a semiconductor body having a semiconductor body portion with a conductivity type determining impurity concentration of the order of at most 10.sup.15 dopant atoms per cm.sup.3, a shallow surface layer of the body portion having a higher doping level than that of the underlying semiconductor body portion, said higher doping level being at least 5 .times. 10.sup.17 atoms per cm.sup.3, an electrode connection to the underlying body portion, and a metal electrode on the shallow surface layer and forming a Schottky barrier with the semiconductor body, the shallow surface layer determining the effective height of the barrier, the depth of the shallow surface layer being much smaller than the thickness of the depletion layer extending from the Schottky barrier in the zero bias condition, whereby the surface layer is substantially depleted of charge carriers and the slope of the reverse current-voltage characteristic is determined by the doping of the underlying semiconductor body portion substantially independently of said shallow surface layer.