Bi-directional Zener diode having a first and second impurity regions groups formed in surface portion of a substrate and a first electrode electrically connected to at least one first impurity regions, and not connected from at least another one

摘要

A bidirectional Zener diode includes a substrate. A first conductivity type base region is formed in a surficial portion of the substrate. A second conductivity type first impurity region is formed in a surficial portion of the base region so as to form a pn junction with the base region. A second conductivity type second impurity region is formed in a surficial portion of the base region in a manner spaced apart from the first impurity region so as to form a pn junction with the base region. A first electrode is arranged at the surface of the substrate. A second electrode is arranged at the surface of the substrate. A dimension of the base region along the surface of the substrate between the first impurity region and the second impurity region is equal to or greater than 4.0 μm and equal to or smaller than 12.5 μm.