One illustrative method disclosed herein includes, among other things, performing a source/drain extension ion implantation to form a doped extension implant region in the source/drain regions of the device, performing an ion implantation process on the source/drain regions with a Group VII material (e.g., fluorine), after performing the Group VII material ion implantation process, forming a capping material layer above the source/drain regions, and, with the capping material layer in position, performing an anneal process so as to form stacking faults in the source/drain regions.