Since VF and IR characteristics of a Schottky barrier diode are in a
trade-off relationship, there has heretofore been a problem that an
increase in a leak current is unavoidable in order to realize a low VF.
Moreover, there has been a known structure which suppresses the leak
current in such a manner that a depletion layer is spread by providing P+
regions and a pinch-off effect is utilized. However, in reality, it is
difficult to completely pinch off the depletion layer. P+ type regions
are provided, and a low VF Schottky metal layer is allowed to come into
contact with the P+ type regions and depletion regions therearound. A low
IR Schottky metal layer is allowed to come into contact with a surface of
a N type substrate between the depletion regions. When a forward bias is
applied, a current flows through the metal layer of low VF
characteristic. When a reverse bias is applied, a current path narrowed
by the depletion regions is formed only in the metal layer portion of low
IR characteristic. Thus, a low VF and low IR Schottky barrier diode can
be realized.