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 (N-2/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 (N-2/Ar>0.15), the hexagonal Te phase first appeared at 160 degrees C, and then the orthorhombic SbN phase appeared at 290 degrees C. The phase separation made it very difficult for these films to switch reversibly between the crystalline and the amorphous phase.