In this paper, we studied the influence of nitrogen implantation dose on both physical and electrical properties in 3C-SiC grown on Si (100) substrate. Scanning Transmission Electron Microscopy characterizations prove that high dose is responsible for amorphization of the implanted layer and the high defect density after annealing. A high V-shape defect density is still found in the implanted layer after an annealing at 1350°C. By lowering the dose, the layer is less damaged and no amorphization is observed. For the different doses, low Specific Contact Resistances are measured using Ti/Ni contacts. The Specific Contact Resistance value decreases from 8x10^-6Ω.cm²for the high dose to 3.2x10^­6Ω.cm²with decreasing the dose. Furthermore, the dopant activation ratio, evaluated by quantitative SSRM measurements, is improved at the same time from 17% (for the high dose) to 60% (for the low dose). This work demonstrates that high activation ratio can be achieved consecutively to a nitrogen implantation at reasonable implantation fluence.