Tristate electrochemical metallization memory based in the hydrogenated nanocrystalline silicon films

Abstract

The hydrogenated nanocrystalline silicon (nc-Si:H) films have been fabricated as resistive switching medium by radio frequency plasma enhanced chemical vapor deposition technology. The constructed Ag/nc-Si:H/Pt structure exhibits stable three nonvolatile resistance states. Tristate resistive states with large ratio 102 and 105, less variation of resistance, and long retention exceeding 2.3 × 105 s are observed in Ag/nc-Si:H/Pt stack. The temperature dependence of high resistance state (HRS) and intermediate resistance state (IRS) both show semiconductor behavior, and the temperature dependence of low resistance state (LRS) represents metallic property. Fitting results demonstrated that the conduction mechanism of HRS, IRS, and LRS showed space charge limited conduction (SCLC), tunneling, and ohmic characteristics, respectively. The discrete Ag filament with Si nanocrystalline and complete Ag filament is proposed to be responsible for the performance IRS and LRS. We supposed that the Ag+ ions prefer to be reduced to Ag atoms near the Si nanocrystalline location. Si nanocrystalline between Ag nanoparticles contribute to the current transport at IRS.