Abstract: An electronic semiconductor apparatus having enhanced resistance to detrimental minority carrier substrate injection comprises:a semiconductor substrate of a first conductivity type material having a first predetermined dopant density, the material having conduction and valence energy state band edges which are separated by an energy band gap;an active area of a second conductivity type formed within the substrate, the active area in operation being a source of injection of minority carriers into the substrate; andan implant region formed beneath the active area to promote recombination of minority carriers with majority carriers within the first conductivity type substrate material in a region of the substrate local to the implant region, the implant region comprising discrete clusters of an implant material which is electrically complimentary to accept minority carriers emanating from the active area, the implant material having an electrically active energy band which is substantially within the energy ban