Comparative study of transient current induced in SiC pn and np diodes by heavy ion micro beams

Oshima, Takeshi; Iwamoto, Naoya; Onoda, Shinobu; Kamiya, Tomihiro; Kawano, Katsuyasu*

In this study, pn and np diodes were fabricated on 6H-SiC epitaxial layers. The transient currents induced in these diodes by the incidence of tens MeV range heavy ion micro beams were collected by the Transient Ion Beam Induced Current (TIBIC) measurement system. The value of Charge Collection Efficiency (CCE) for the SiC diodes was obtained by analyzing the transient currents. As a result using 9 MeV-oxygen ions, the CCE value of around 85 % was obtained from both pn and np diodes. Since the CCE value includes non-ionizing energy loss as well as the decay of charge in the measurement system, the obtained CCE value suggests that SiC pn as well as np diodes are suitable for particle detectors. For ion species dependence, the values of CCE for both pn and np diodes decrease with increasing atomic number of incident ions. This decrease in CCE by heavy ion incidence can be interpreted in terms of Auger recombination in dense electron-hole pairs.