Nitrogen incorporation on the crystallization temperature of silver-doped Ge45Te55 solid-electrolyte films for PMC memory applications

A programmable metallization cell (PMC) memory structure with silver-saturated GeTe solid-electrolyte films doped by nitrogen was prepared on a TiW bottom electrode by a cosputtering technique at room temperature. The Ge45Te55 solid-electrolyte films deposited with various N-2/Ar flow ratios showed an increase of crystallization temperature and especially, the electrolyte films deposited at N-2/Ar ratios above 30% showed a crystallization temperature above 400 degrees C, resulting in survival of a back-end process in semiconductor memory devices. A PMC memory device with nitrogen-doped Ge45Te55 solid electrolytes shows reproducible memory characteristics based on resistive switching at threshold voltage of 1.2 V with high R-off/R-on ratios. (c) 2006 The Electrochemical Society.