Electrical and structural properties of TaSiN electrode for phase change random access memory

Characteristics of tantalum silicon nitride (TaSiN) thin films have been investigated as an electrode material for Ge2Sb2Te5 chalcogenide phase change material. The films were deposited by co-sputtering system in which the ratio of tantalum nitride to silicon was controlled by the plasma power on each target. The TaSiN films showed tunable resistivity from 260 to 560 μΩ cm with increasing Si content. From the evaluation of PRAM cell structures consisting of the TaSiN and the Ge2Sb2Te5, we found that the SET voltages are nicely correlated with the resistivity of the TaSiN. Moreover, the sensing margin (resistance ratio: RSET/RRESET) turned out to be good for practical application.