The application of high-voltage reverse current to voltage characteristics
for characterization of ultra-deep radiation defect profiles in ion irradia
ted silicon p-i-n diodes is presented. Theoretical analysis shows that moni
toring of the reverse current gradient with increasing bias can give, in co
mbination with Deer Level Transient Spectroscopy (DLTS) and Capacitance-Vol
tage (C-V) measurement, quantitative information about the distribution of
generation defect centres with the highest emissivity. The method is subseq
uently used for characterization of deep-level profiles in p(+)pnn(+) power
diodes irradiated by He2+ ions with energies 11-22 MeV and fluences 2.5 x
10(9)-1.2 x 10(10) cm(-2). The results show that the method can non-destruc
tively determine the concentration profile of divacancies, the dominant gen
eration centre in helium irradiated silicon, in the depths of the device wh
ere application of other methods usually fails. (C) 1999 Elsevier Science B
.V. All rights reserved.