Cr_xSb₂Te₁ materials for phase change memory with high speed and good thermal stability performance

Abstract

Phase change memory (PCM) is one of the most promising candidates for the next-generation non-volatile memory, of which phase change material as the storage media is the key factor. In this paper, we proposed a novel phase change material Cr_xSb₂Te₁, which exhibits faster phase transition speed, better thermal stability and higher reliability compared with traditional Ge₂Sb₂Te₅. With the increase of doped-Cr, the grain sizes are refined and the volume change rate decreases. What’s more, in the composition range studied, the crystal structure of Cr_xSb₂Te₁ films is single hexagonal phase without phase separation. For preferred Cr_0.25Sb₂Te₁ and Cr_0.41Sb₂Te₁ films, the resistance ratios between amorphous and crystalline states are up to two orders of magnitude or more; the temperatures for 10-year-data-rentation are 102.7 and 128.4 °C, respectively, showing good thermal stability performance. For the PCM cells based on the preferred Cr_0.25Sb₂Te₁ and Cr_0.41Sb₂Te₁ films, the threshold current/threshold voltage are about 4 μA/1.3 V and 4 μA/1.2 V, respectively; and when the voltage pulse width is short as 30 ns, the SET/RESET voltages are 1.7/3.3 and 1.9/4.5 V, respectively, showing high speed application potential for PCM.