Properties and applications of diffused junction silicon rectifiers

Developments in the diffusion technology of silicon p-n junctions have made feasible new rectifiers of outstanding performance. Current densities greater than 1,000 amperes/cm²are obtained at one volt forward bias; the same elements have reverse breakdown in excess of 200 volts. The oven diffusion method permits the critical process steps of barrier formation and contact application to be done on entire silicon slices, which may then be cut into elements of any desired size for assembly into completed devices. The use of high resistivity silicon as starting material, combined with a long diffusion cycle, results in relatively low junction capacitance. Signal type diodes have been prepared with a forward current greater than one ampere at one volt, reverse current less than one microampere at two hundred volts, and capacitance less than ten micromicrofarads at ten volts reverse bias.