Impact of Temperature on the Resistive Switching Behavior of Embedded HfO₂-Based RRAM Devices

Back-end-of-line integrated <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">1 × 1\ ² \ TiN/HfO₂/ Ti/TiN</tex></formula> MIM memory devices in a 0.25- <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX"></tex></formula> 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 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">I</tex></formula> – <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">V</tex></formula> characteristics in fresh devices are attributed to the Poole–Frenkel mechanism with an extracted trap energy level at <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">φ ≈ 0.2\ eV</tex> </formula> below the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">HfO₂</tex></formula> 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 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">I</tex></formula> – <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">V</tex></formula> 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.