The distribution of secondary defects in B+ or Al+ implanted 4H-SiC is examined using TEM and SIMS. They distribute from the projected range for low dosage case and from near surface for high dosage case, and they distribute to the depth at the concentration of about 10% of the maximum dopant concentration. These secondary defects are extrinsic dislocation loops and the distribution of them is closely related to that of excess Si and C interstitials formed by implantation.