Storage transistors for flash memory areas in semiconductor devices may be provided on the basis of a self-aligned charge storage region. To this end, a floating spacer element may be provided in some illustrative embodiments, while, in other cases, the charge storage region may be efficiently embedded in the electrode material in a self-aligned manner during a replacement gate approach. Consequently, enhanced bit density may be achieved, since additional sophisticated lithography processes for patterning the charge storage region may no longer be required.