Crystalline recovery mechanism in the activation annealing process of Al implanted 4H-SiC crystals were experimentally investigated. Annealing temperature and annealing time dependence of acceptor activation and activated hole’s behavior were examined. Poly-type recovery from the implantation induced lattice disordering during the annealing was investigated. The existence of meta-stable crystalline states for acceptor activation, and related scattering centers due to annealing is reported To achieve 100% acceptor activation and to reduce strain after ion implantation, annealing at 2000°C for 10 min. was required.