C-N-codoped Sb_2Te_3 chalcogenides for reducing writing current of phase-change devices

摘要

In this work, doping C and codoping C and N into the Sb_2Te_3 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 Sb_2Te_3 film, while it appeared after codoping C and N into Sb_2Te_3. 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 Sb_2Te_3 was about two orders of magnitude higher than that of Sb_2Te_3. 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 Sb_2Te_3 as the active medium can significantly drop to about 1/8 of that of the Sb_2Te_3 based one.