$\hbox {ZrTiO}_{x}$ -Based Resistive Memory With MIS Structure Formed on Ge Layer

Resistive random access memory (RRAM) cells with a thin oxygen-deficient ZrTiO_x, film topped by a Ti oxygen- gettering layer and a Pt electrode were fabricated on n-Ge layer, and the switching mechanism, as well as electrical characteristics, was explored. The RRAM cells demonstrate a stable bipolar switching behavior without the requirement of a forming process. Because of the existence of a larger amount of interface traps which would trap carriers and help build a favorable electric field for the drift of oxygen vacancies, the RRAM cells possess lower SET and RESET voltages compared to those fabricated on n-Si layer. With many promising properties such as a large sensing margin of 300 times, a high operation speed of 250 ns, a robust endurance of 10⁵ cycles, and a long data retention time of up to 10 years, the ZrTiO_x-based RRAM cells exhibit a promising perspective as nonvolatile memory devices for Ge-based technology.