Observation of transient current induced in silicon carbide diodes by ion irradiation

The high-speed current transients induced in SiC p-n diodes by 9 MeV Ni2+ and 12 MeV Ni3+ were measured using transient ion beam induced current (TIBIC). The amplitude of the TIBIC signals increases with increasing bias voltage. The transient current fall-time reduces with increasing bias voltage. These results are attributed to the increase in the electric field and the space-charge region with bias. However, the charge collection efficiency is below 100% even if the depletion width is greater than the Ni ion range. This can be attributed to the large nuclear stopping of Ni and recombination of the highly dense electron-hole pairs in the space-charge region. Our result indicates that pulse height defect (PHD) plays a significant role in the charge collection mechanism in these SiC p-n diodes for highly ionizing particles. (C) 2003 Elsevier Science B.V. All rights reserved.