Schottky barrier diode

A Schottky barrier diode, comprising:

• a semiconductor substrate having a first conductivity type;
• an epitaxial layer having a first conductivity type which is formed on the semiconductor substrate and has an impurity concentration lower than that of the semiconductor substrate;
• a Schottky metal which is in Schottky-contact with a surface of the epitaxial layer;
• a peripheral trench formed by digging from the surface of the epitaxial layer in a boundary portion between an active region where the Schottky metal is in Schottky-contact with the surface of the epitaxial layer and a peripheral region outside of the active region;
• an insulating film formed directly on an entire area of inner wall surfaces of the peripheral trench and not upon the surface of the epitaxial layer;
• a conductor which is not upon the surface of the epitaxial layer, is connected to the Schottky metal and is opposite to the entire area of the inner wall surfaces of the peripheral trench via the insulating film;
• and
• wherein the inner wall surfaces of the peripheral trench include side surfaces and a bottom surface of the peripheral trench;
• and
• wherein a depth of a depletion layer formed immediately below the peripheral trench at a time of applying a reverse voltage is the SAME as a depth of a depletion layer formed in the active region.