Please enable JavaScript.

Coggle requires JavaScript to display documents.

Paper 7 Reviewer-3 "SIM^2RRAM:" (Classification of RRAM cell…

- - - - 1. electrochemical
        
        usually bipolar devices, in which cations
        are dragged by the electric field applied
        
        Metallic ions from one electrode (the active electrode) drift across the insulator and form a CF
        
        These devices are called electrochemical metallization memories (ECM-RRAM) and/or conductive bridge RAM (CBRAM).
        
        Process:
        
        the metallic electrodes that provide cations with better mobility in the RS insulator are Ag, Ni, or Cu.
        
        The metallic ions coming from the active electrode polarized under positive bias can diffuse into the insulator, and when they reach the opposite electrode,
        they get reduced and form CFs that bridge the electrodes triggering a set process.
        
        By applying negative bias to the same electrode, the metallic atoms that form CF are oxidized and diffuse provoking the disruption of the CF and resetting the
        conductance.
        
        Also explains it in geat detail and why complaince current is used
        
        When the first dielectric breakdown
        (BD) is reached (a process called forming or electroforming in RRAM), the filament expands laterally due to ion migration (see Fig. 3c) [16,108]. In order to avoid severe damage of the dielectric and irreversible BD, a current limitation is often used [168].
      - 2. valence change,
        
        based on the generation
        of mobile oxygen ions [13] within the insulator help the
        formation of CFs made of oxygen vacancies/
        
        devices have been called valence change memories (VCM-RRAM).
        -the electrodes selected are normally inert (e.g.,
        Pt, W, or TiN
        
        In general, when the electrodes
        are selected to be active metals, theMIM cell works as
        ECM-RRAM; on the contrary, the use of inert metals enables its use as VCM-RRAM.
        
        The differences are linked to the origin of the ions:
        In ECM-RRAM, they come from the active electrodes, while in VCM-RRAMs they consist of oxygen ions formed in the insulator when exposed to an electric field. This generates an accumulation of ions close of the top electrode named reservoir
      - 3. thermochemical
        
        devices are called (TCM-RRAM)
        
        normally show thermally assisted unipolar RS
        
        Formation and rupture of CF by the ions generation and recombination processes inside the insulator by the chemical reaction of reduction-oxidation (redox reaction)
        
        Redox reaction is boosted by local temp. increase due to joule heating
        
        In addition, the ion thermal diffusion from the CF to the surrounding dielectric is taken into account