The encapsulating annealing of N+ implanted 4H-SiC(0001) is performed using diamondlike- carbon (DLC) films for the suppression of surface roughening. 4H-SiC(0001) sample with an off-orientation of 8o is multiply implanted by N+ with energy ranging from 15 to 120 keV at a total dose of 2.4×1015 cm-2 at room temperature. DLC films with thickness ranging from 0.3 to 1.8 μm are deposited on the surface of implanted sample using plasma-based ion implantation equipment with C2H4 gas. The DLC capped sample is annealed at 1500 oC for 5 min using IR image annealer. After annealing, DLC film is removed by the oxidization. The sample capped by DLC film with a thickness of 0.3 μm shows the root mean square (RMS) surface roughness of 0.6 nm while the annealed sample without DLC film shows RMS surface roughness of 5.2 nm. As the thickness of DLC film is increased from 0.3 to 1.8 μm, the RMS surface roughness is decreased from 0.6 to 0.2 nm.