Data to replicate the experimental data plots in the paper: Fig. 1d, e: AFM scans of SIL before the etching and after the etching, possibility to see how the mask changed in the etching process; Fig. 2a, b, c: Confoscal scan of the all SIL, g2 measurements of one defect inside the sils and relative ODMR measurements related to Vsi in SiC in the SIL; Fig. 3a, b: statistics of centers inside the sils according to the enhancement, maximum enhancement reached for one center inside the SIL compared to the one outside