Low-consumption phase change material with good data retention selected from SbxTe

Various compositions of SbxTe phase-change films have been investigated by means of in situ temperature-dependent resistance measurement. Although crystallization temperature of Sb3Te is about 536 K, a little lower than those of Sb2Te and Sb4Te, it has a better data retention performance than the other two compositions. X-ray diffraction patterns imply that poly-crystalline structures of Sb-Te alloys are all hexagonal, and phase separation appears in SbTe3, Sb2Te, Sb3Te and Sb4Te alloys. Sb2Te and Sb3Te have been selected for phase-change random access memory devices. RESET voltage for Sb3Te is 1.2 V when the voltage pulse width is 50 ns, 0.3 V lower than that for Sb2Te. By using the voltage pulse width of 200 ns, Sb3Te needs 1.8 V and 4 V to complete SET-RESET performance, 0.4 V and 0.5 V lower than Sb2Te respectively. It indicates that Sb3Te is more suitable for the application of phase-change random access memory.