Damage formation and recovery in temperature helium implanted 4H–SiC

He+ ions were implanted in 4H–SiC at 750 °C with a fluence of 1×1017 cm−2. Bubbles that appear in strata parallel to the surface are readily formed in the as-implanted state. The bubble formation and the dilatation of the c-axis all over the ion track induce the swelling of the implanted surface. Upon annealing at 1500 °C–30 min, the structure is relaxed, the density of cavities decreases and their mean diameter increases. The increase of the step height after annealing suggests the migration of both the interstitials and vacancies.