NONVOLATILE MEMORY EFFECTS IN NITROGEN-DOPED TETRAHEDRAL AMORPHOUS-CARBON THIN-FILMS

Electrical measurements of nitrogen doped tetrahedral amorphous carbon (ta-C:N) thin films have revealed a reversible nonvolatile memory eff ect, related to the excitation and de-excitation of electrons between deep acceptor states and shallow donor states within the mobility gap. This effect is characterized by changes in the small signal film cond uctivity of up to 10 times, and has been used to fabricate 1-bit memor y cells with effective memory retention times in the order of several months. (C) 1998 American Institute of Physics. [S0021-8979(98)05522-4 ].