Role of the electrode metal, waveform geometry, temperature, and postdeposition treatment on SET and RESET of HfO2-based resistive random access memory 1R-cells: Experimental aspects

An experimental characterization of SET and RESET operations in HfO2-based resistive random access memory cells in a wide range of conditions is addressed. In particular, the influence of the electrode metal, the switch waveform geometry and the measurement temperature is considered. A postdeposition annealing at high temperature is also performed on a set of samples. The waveform geometry affects the RESET and SET voltages, in the sense that shorter raise times make less effective the ion diffusion, which, instead, is not influenced by the electrode metal. On the contrary, the presence of a highly reactive electrode (Ti) reduces the switch and the forming voltage respect to TiN and Pt electrodes, thanks to the greater oxygen reservoir, but does not seem to have a role on the ion diffusion. The high temperature annealing concurs in reducing the forming voltage, due to the formation of grains on whose boundaries the generation of oxygen vacancies is favored. Also the electron conductance is affected by the postdeposition treatment and the sensitivity on the measurement temperature is discussed.