The fabrication of junctions with very low minority-carrier injection ratios and reasonably good diode characteristics on p-type silicon is reported. These junctions were formed by growing an ultrathin oxide layer on a monocrystalline substrate, depositing polysilicon heavily doped in situ with phosphorus over the oxide, overlaying the polysilicon with aluminum, and then annealing the resulting sandwich structure at temperatures in the range 400-450 degree C. The junctions can exhibit leakage current densities below 10** minus **6 A multiplied by (times) cm** minus **2 at moderate reverse bias and reverse breakdown voltages in excess of 20 v. The absence of minority-carrier injection has been demonstrated by diode reverse recovery transient measurements and by the fabrication of bipolar transistors employing these junctions as emitters.