This study investigates the role of ion implantation in suppressing stacking fault (SF) expansion in SiC epitaxial layers, a significant issue in the adoption of high-voltage SiC bipolar devices. The research focuses on the effects of helium and proton implantation on basal plane dislocations (BPDs). Using helium due to its low reactivity and tendency to diffuse out during annealing allows for an assessment of point defects introduced by ion implantation alone. Commercial N-type 4H-SiC epitaxial substrates were implanted with helium or proton ions, followed by annealing and analyzed using grazing incidence synchrotron reflection X-ray topography.Results showed that while SF expansion was completely suppressed in some cases, a slight expansion was still observed in others, suggesting that the density of point defects plays a critical role. The ion implantation simulation indicated that the defect density from proton implantation was significantly higher than from helium. This implies that the suppression of SF expansion and dislocation movement is largely due to the point defects rather than the type of ion used. High-temperature observations of heavily nitrogen-doped SiC crystals confirmed that the interaction between dislocations and point defects can inhibit bipolar degradation, pointing to a similar mechanism in ion-implanted layers.