Reactive ion etching as cleaning method post chemical mechanical polishing for phase change memory device

In order to improve nano-scale phase change memory performance, a super-clean interface should be obtained after chemical mechanical polishing (CMP) of Ge2Sb2Te5 phase change films. We use reactive ion etching (RIE) as the cleaning method. The cleaning effect is analysed by scanning electron microscopy and an energy dispersive spectrometer. The results show that particle residue on the surface has been removed. Meanwhile, Ge2Sb2Te5 material stoichiometric content ratios are unchanged. After the top electrode is deposited, current-voltage characteristics test demonstrates that the set threshold voltage is reduced from 13 V to 2.7 V and the threshold current from 0.1 mA to 0.025 mA. Furthermore, we analyse the RIE cleaning principle and compare it with the ultrasonic method.