Hot-electron conduction in ovonic materials

Electric conduction in ovonic materials is analyzed with special attention to chalcogenide glasses used for phase-change memories. A general theory is presented based on plausible microscopic assumptions. Electric field, carrier concentration, and electron temperature along the device, as well as diffusion and Poisson self-consistency, are considered. The effect of different ranges of localized levels in the gap is analyzed. The results account for and interpret all main experimental findings in phase-change memory cells.

► Carrier transport in ovonic materials is modeled by means of trap-limited conduction.
► The effect of the energy levels of the traps is evaluated.
► Results fit experimental data.
► The threshold voltage is attributed to carrier heating.