Silicon p+-n junction diodes irradiated with 3.5MeV electrons (to a dose of 4 x 1016/cm2) were studied. The diode inductance (L) was measured at a frequency f = 1MHz with the amplitude of alternating current equal to 0.25mA. Simultaneously with measurements of L at alternating current, a direct current was passed through the forward-biased diode, which brought about the injection of minority charge carriers into the base. In order to identify both of the mechanisms that gave rise to the inductive-type impedance in irradiated diodes with the p +-n junction and the main radiation defects that were directly involved in the formation of this impedance, irradiated samples were annealed isochronously at 225 to 375C with subsequent study of the main characteristics of the defects by deep-level transient spectroscopy. It was shown that the inductive-type impedance in irradiated diodes was caused by the processes of capture and retention of charge carriers injected into the base at the trapping centres for a time ∼1/2f, i.e., for a half-period of oscillations. It was also shown that the trapping centres were the vacancy-oxygen complexes introduced by irradiation with electrons.

Negative Capacitance (Impedance of the Inductive Type) of Silicon p+-n Junctions Irradiated with Fast Electrons. N.A.Poklonski, S.V.Shpakovski, N.I.Gorbachuk, S.B.Lastovskii: Semiconductors, 2006, 40[7], 803-7