C–N-codoped Sb2Te3 chalcogenides for reducing writing current of phase-change devices

Abstract

In this work, doping C and codoping C and N into the Sb2Te3 traditional chalcogenide were investigated to reduce the writing current of the phase-change device using a chalcogenide as the active medium. No face-centered-cubic (FCC) structure was observed in the C-doped Sb2Te3 film, while it appeared after codoping C and N into Sb2Te3. The FCC crystallite size greatly reduced from 6.5 to 3.5–3.8 nm after codoping. In particular, the resistivity of FCC C–N codoped Sb2Te3 was about two orders of magnitude higher than that of Sb2Te3. The effect of the property of the chalcogenide on the writing current of the phase-change device was analyzed by the finite element method. The analysis showed that the writing current of the device using C–N-codoped Sb2Te3 as the active medium can significantly drop to about 1/8 of that of the Sb2Te3 based one.