A problem in related art according to which an increase in leak current cannot be avoided in order to obtain a low forward voltage VF as forward voltage VF and reverse leak current IR characteristics of a Schottky barrier diode are in a trade-off relationship is hereby solved by forming a Schottky barrier diode using a metal layer comprising a Schottky metal layer of Ti including a small amount of Al. Consequently, a low reverse leak current IR can be obtained without causing a large increase in the forward voltage VF of pure Ti such that power consumption can be reduced by suppressing forward power loss and decreasing reverse power loss.