Impact of temperature on the resistive switching behavior of embedded HfO<inf>2</inf>-based RRAM devices

Back-end-of-line integrated 1 × 1 μm2 TiN/HfO 2/Ti/TiN MIM memory devices in a 0.25-μm complementary metal-oxide-semiconductor technology were built to investigate the conduction mechanism and the resistive switching behavior as a function of temperature. The temperature-dependent I-V characteristics in fresh devices are attributed to the Poole-Frenkel mechanism with an extracted trap energy level at φ ≈ 0.2 eV below the HfO2 conduction band. The trap level is associated with positively charged oxygen vacancies. The electroformed memory cells show a stable bipolar switching behavior in the temperature range from 213-413 K. The off -state current increases with temperature, whereas the on-state current can be described by a weak metallic behavior. Furthermore, the results suggest that the I-V cycling not only induces significant changes in the electrical properties of the MIM memory devices, i.e., the increase in the OFF-state current, but also stronger temperature dependence. The temperature effect on the ON-state and OFF-state characteristics is modeled within the framework of the quantum point-contact model for dielectric breakdown using an effective temperature-dependent confinement potential. © 2006 IEEE.