Charge generated in 6H–SiC n+p diodes by MeV range heavy ions

Charge induced in 6H–SiC diodes by heavy ions, oxygen (O), silicon (Si), nickel (Ni), and gold (Au), at energies from 6 to 18 MeV was evaluated using a Transient Ion Beam Induced Current (TIBIC) measurement system. In the case of heavy ions with relatively light mass, such as O and Si, the high Charge Collection Efficiency (CCE) was obtained, although the CCE decreased with increasing atomic numbers. The CCE of 6H–SiC n+p diodes irradiated with Au ions was approximately 40%. From the calculation using the modified Kobetich and Katz (KK) model, it is found that dense electron–hole (e–h) pairs were generated in SiC by irradiation of ions with heavy mass, such as Ni and Au, and the density was much higher than that in SiC irradiated with O ions. The decrease in the CCE due to ion irradiation with heavy mass, such as Ni and Au can be interpreted in terms of the annihilation of e–h pairs in plasma due to the Auger recombination.

Research Highlights
► High Charge Collection Efficiency (CCE) is observed for 6H–SiC diodes by O ion incidence.
► The CCE value decreases with increasing atomic numbers.
► The CCE value is approximately 40% in the case of Au ion incidence.
► This behavior can be interpreted in terms of the annihilation of e–h pairs in plasma.