Implantation damage in heavy gas implanted 4H-SiC

Single crystals of SiC were implanted with heavy inert gases (Xe, Ar) at elevated temperatures (300-800 °C) and for a large range of fluence (1 × 1012-1 × 1015 ions cm−2). Thermodesorption measurements suggest that gas is trapped by implantation-induced vacancy-type defects impeding any gas diffusion. The damage accumulation versus dose was studied through the tensile elastic strain determined by using X-ray diffraction. Results show that at low dose the strain is predictable via a thermally activated direct impact model. The low thermal activation energy at saturation suggests a dynamic recovery process dominated by the migration of interstitial-type defects as its relaxation during post thermal annealing. As compared with light-gas implantation the heavy-gas to defect ratio is low enhancing the formation of strongly perturbed zones rather than the formation of bubble precursors.