| 摘要 |
PURPOSE:To restrain the increase in the voltage effect in the normal direction by a method wherein semiconductor region in higher impurity concentration than that in the substrate region in the same conductivity type as that of the substrate region is formed in the substrate region beneath a semiconductor region in the inverse conductivity type CONSTITUTION:A semiconductor substrate 1 is provided with a pair of main surfaces 11, 12, an n type semiconductor region 13, another n type semiconductor region 14 in higher impurity concentration than that in the semiconductor region 13, a p type semiconductor region 15 in a hollow circular shape located in the semiconductor region 13 from one main surface 11 in higher impurity concentration than that in the semiconductor region 13 and an n type semiconductor region 20 in higher concentration than that in the semiconductor region 13. Next, a main electrode 2 effects a Schottky junction at the interface with the semiconductor region 13 while coming into ohmic contact with the part excluding the parts covered with the semiconductor region 15 and an insulating film 14. Besides, another main electrode 3 comes into ohmic contact with the semiconductor region 14. Through these procedures, the current passing through the semiconductor 14 can be divided into the two currents i.e., one passing through the shortest distance to the Schottky junction part and the other passing through the low resistant semiconductor region 20 thereby enabling the increase in the voltage effect in the normal direction to be restrained. |
