Improvement of CBRAM Resistance Window by Scaling Down Electrode Size in Pure-GeTe Film

TaN-pure-GeTe-Cu bipolar switching devices which can be adaptable to semiconductor processes were fabricated as a function of top-electrode sizes (0.2, 0.4, 10, and 50 mum). The on/off resistance change ratio increased highly with decreasing electrode size. In particular, the on/off resistance change ratio was about 10³ when the electrode size was scaled down to 200 nm. We obtained the characteristics of conductive bridging memory cell using pure-GeTe film without any doping of Cu or Ag; we also determined the reason for the enhancement of the on/off resistance change ratio when scaling down the electrode size.