Semiconductor memory device using junction short type programmable element.

摘要

A semiconductor memory device using a junction short type programmable element comprises an epitaxial layer (l2) formed on a semiconductor substrate (ll), the epitaxial layer having an opposite conductive type to that of the semiconductor substrate,the epitaxial layer being a collector region; a base region (l4) having the same conductive type as the substrate formed in the epitaxial layer; a first emitter region (l5) having an opposite conductive type to that of the base region, formed in the base region; an insulating isolation region (l3), formed in said epitaxial layer and around the base region; a second emitter region (l5a) having a higher impurity concentration than that of the first emitter region and the same conductive type as the of the first emitter region, formed in the first emitter region in such a manner that the second emitter region penetrate the first emitter region upward and downward and extends to the interior of the base region (l4) so that a writing current flows concentratedly at the second emitter region.