Characterization of nitrogen-doped Sb2Te3 films and their application to phase-change memory

In this study, sputtered undoped and nitrogen doped Sb2Te3 (ST and STN) films were systematically investigated by x-ray diffraction (XRD) and resistance measurements. Their application to lateral phase-change memory (PCM) is presented as well. The STN film sputtered at a flow rate ratio (N2∕Ar) of 0.07 proved to have both high stability and low power consumption, implying its high performance in PCM applications. In the STN films (N2∕Ar>0.15), the hexagonal Te phase first appeared at 160 °C, and then the orthorhombic SbN phase appeared at 290 °C. The phase separation made it very difficult for these films to switch reversibly between the crystalline and the amorphous phase.