Investigation of amorphization energies for heavy ion implants into silicon carbide at depths far beyond the projected ranges

Abstract

At ion energies with inelastic stopping powers less than a few keV/nm, radiation damage is thought to be due to atomic displacements by elastic collisions only. However, it is well known that inelastic processes and non-linear effects due to defect interaction within collision cascades can significantly increase or decrease damage efficiencies. The importance of these processes changes significantly along the ion trajectory and becomes negligible at some distance beyond the projected range, where damage is mainly caused by slowly moving secondary recoils. Hence, in this region amorphization energies should become independent of the ion type and only reflect the properties of the target lattice. To investigate this, damage profiles were obtained from α-particle channeling spectra of 6H-SiC wafers implanted at room temperature with ions in the mass range 84⩽M⩽133, employing the computer code DICADA. An average amorphization dose of (0.7±0.2)dpa and critical damage energy of (17±6)eV/atom are obtained from TRIM simulations at the experimentally observed boundary positions of the amorphous zones.