Reduction of emitter-collector leakages by ion implantation

An implantation technique is described in which the implantation is done through a thin oxide layer into the emitter area of a simple NPN bipolar silicon device prior to emitter arsenic diffusions. Experimental results indicate that emitter-collector leakages can be reduced for argon and xenon implanted devices, and that the ratio of collector to base current for implanted devices can be the same as for nonimplanted devices if the implantation damage is confined to a shallow region near the silicon surface. With the aid of transmission electron microscopic studies, a mechanism for this implantation technique is suggested.