High-dose ion implantation of phosphorus into 4H-SiC (0001) has been investigated with three different ion fluxes ranging from 1.0 to 4.1 ×1012P+cm-2·s-1 and keeping the implantation dose constant at 2.0×1015 P+cm-2. The implantations are performed at room temperature and subsequently annealed at 1500℃. Photoluminescence and Raman scattering are employed to investigate the implantation-induced damages and the residual defects after annealing. The electrical properties of the implanted layer are evaluated by Hall effect measurements on the sample with a van der Pauw configuration. Based on these results, it is revealed that the damages and defects in implanted layers can be greatly reduced by decreasing the ion flux. Considering room temperature implantation and a relatively low anealing temperature of 1500℃, a reasonably low sheet resistance of 106Ω/□ is obtained at ion flux of 1.0×1012P+cm-2·s-1 with a donor concentaration of 4.4×1019cm-3.