Strain and amorphization under light-ion implantation in SiC

Consequences of ion implantation on the strain build-up and the crystalline-to-amorphous transition have been studied in SiC as a function of the energy of the incident He ions. The ratio of strain to displacements per atom (dpa) determined from X-ray diffraction (XRD) measurements and simulations decreases with ion energy whilst a significant recombination of defects is ruled out. Transmission electron microscopy (TEM) experiments show that this resistance to strain occurring with increasing energy of implantation is concomitant with a resistance to amorphization. The crystalline-to-amorphous transition is not correlated with a threshold deposited nuclear energy or defect concentration as calculated by ion implantation computer codes but occurs once a critical strain estimated at about 10% is reached.