Comparative Hall effect investigations are conducted either on N+-/ P+-implanted or on (N++P+)-coimplanted n-type 4H-SiC films prepared in Al-doped 4H-SiC epilayers. The implanted donor concentrations varied between 3.2x10(18)cm(-3) and 2.4x10(20)cm(-)3. It turns Out that there is a critical donor concentration of approximately 3x10(19)cm(-3); N+-implantations are superior below and P+-implantations above this critical value.