Double Injection Diodes and Related DI Phenomena in Semiconductors

Experimental studies of double injection (DI) negative resistance phenomena in GaAs, Si, and Ge are presented. V-I characteristics, switching, trapping, and photosensitivity properties of GaAs DI p-i-n diodes, fabricated by diffusion and alloying processes on semi-insulating crystals and in other cases fabricated via epitaxial processes with Cu-doped i regions, are described. Similar studies and data are presented on Si DI p-i-n diodes prepared via diffusion and/or alloying processes. Silicon DI p-i-n diodes are described which have been doped with various deep level impurities such as Au, Zn, Cd, or Co and which, depending upon the kind and concentration of deep level impurities, display a wide range of behavior including useful photosensitivity, switching, and voltage regulation properties. Brief mention is made of Ge DI p-i-n diodes fabricated on n-type crystals counter-doped with Cu, Fe, Ni, Co, or Mn. A comparison is made between experimental results and current theories of double injection effects. As might be expected, existing theories do not completely account for the experimental situation, e.g., breakdown to constant voltage in certain units and phenomena which seem closely related to plasma effects. In addition to various practical implications, including possibilities for a noninteracting diode negative resistance matrix, low voltage regulator diodes, photosensitive charge-storage diodes, and higher power microwave switching p-i-n diodes, the significance of deep level doping and possible and actual effects (e.g., secondary switching effects) on epitaxial Si devices are described.