In an attempt to substantiate our previous findings of boron deactivation and/or donor complex formation due to high-dose Ge and C implantation, SiGe and SiGeC layers were fabricated and characterized. Cross-sectional transmission electron microscopy indicated that the SiGe layer with peak Ge concentration of 5 at% was strained; whereas, for higher concentrations, stacking faults were observed from the surface to the projected range of Ge as a result of strain relaxation. Results of spreading resistance profiling were found to be consistent with the model of dopant deactivation due to Ge implantation and subsequent solid phase epitaxial growth of the amorphous layer. Furthermore, for unstrained SiGe layers (Ge peak concentration ≥7 at%), formation of donor complexes is indicated. Preliminary photoluminescence results correlate with the spreading resistance profiling results and indicate shallow donor complex formation.