Study of Memristors Based on Silicon-Oxide Films Implanted with Zinc

Nanoclusters of metals and metal-oxide compounds in various solid-state matrices can find application in promising microelectronic devices. The results of studying memristors based on silicon-oxide films implanted with 64Zn+ ions (dose of 3 × 1016 cm–2 and energy of 40 keV) at room temperature and annealed at temperatures from 400 to 800°C in an oxidizing environment are presented. The concentration profiles of implanted zinc, as well as matrix elements, silicon and oxygen, are obtained via the Rutherford backscattering spectroscopy of He+ ions with an energy of 2 MeV. The surface topology is investigated using a scanning probe microscope in the atomic-force-microscopy mode and Kelvin mode. After implantation, sample-surface smoothing occurs due to sputtering. Further, during thermal annealing, the surface roughness increases and broadening of the roughness distribution is observed in comparison with the implanted sample. The images of the surface potential obtained in the Kelvin mode differ in terms of the sign of the signal: positive, for the initial sample, and negative, for the sample annealed at 800°C. The phase composition of the films is studied using X-ray diffraction analysis in the grazing geometry. It is found that crystalline phase of Zn was formed in the SiO2 film after implantation. After annealing at 800°C, the Zn phase is mainly transformed into the zinc silicide (willemite) Zn2SiO4 phase and partially into the ZnO phase. The analysis of small peaks in the diffraction patterns carried out using the EVA program indicates that the β-Zn2SiO4 and Zn1.95SiO4 phases are formed in the samples.