Deep levels created in n-epitaxial silicon by alpha particle irradiati
on in the dose range from 10(9) to 10(13) particles/cm(2) have been in
vestigated by the deep level transient spectroscopy technique and capa
citance-voltage profiling. Under low fluence irradiation at least four
main electron traps have been observed. With further increase in irra
diation fluence, two new levels located at E-c - 0.56 eV and E-c - 0.6
4 eV appear on the high-temperature side of the DLTS signal. The slope
change observed in the amplitude variations of the singly negative ch
arge state of the divacancy versus the dose takes place when these two
new levels appear. This suggests that both are multivacancy-related d
efects. After annealing at 350 degrees C for 15 min, all electron trap
s have disappeared. Moreover, no shallow levels are created during the
annealing.