Comparative Hall effect measurements are conducted on n-type films generated by N- or P-donors, which are coimplanted together with Si+-, C+- or Ne+-ions into Al-doped 4H-SiC epilayers. It is demonstrated that the annealing process of coimplanted P atoms is governed by the site-competition-effect, while the electrical activation of coimplanted N atoms is dominated by the formation of thermally stable and electrically neutral complexes.