Fabrication of multi-level switching phase change nano-pillar device using InSe/GeSbTe stacked structure

The InSe/GeSbTe stacked phase change materials were investigated at nano-scale for multi-level switching with a large sensing margin and fast switching. The 200 nm nano-pillar devices of InSe material and InSe/GeSbTe materials were fabricated using NIL, and its electrical properties were characterized using conducting AFM system, that was connected to a pulse generator and a voltage source. In case of InSe based nano-pillar device, it was evaluated that the fast switching speed (<100 ns) and large difference of resistance on–off ratio (>10,000) and exhibited only bi-level switching characteristics. In case of the InSe/GeSbTe PCMs structure exhibited three levels of resistance state with a few hundred times of difference between them with 100 ns reset pulse.