A Correlation Between Oxygen Vacancies and Reliability Characteristics in a Single Zirconium Oxide Metal-Insulator-Metal Capacitor

Abstract

A correlation between reliability characteristics and failure mechanisms for time-dependent dielectric breakdown for a single ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> metal-insulator-metal capacitor has been studied. Frenkel-Poole emission was the dominant mechanism in the high electric field region. The extracted dynamic constant and trap energy level were 4.013 and 0.963 eV, respectively. The variation of α as a function of stress time under constant voltage stress (CVS) gradually decreased. Moreover, ΔC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">stress</sub> /C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> under dynamic voltage stress was much greater than under CVS, which indicates that new defects and charge trapping could be generated in high-κ (HK) dielectric under dynamic voltage stress under negative voltage as well as positive voltage. The extracted average value of the Weibull slope (β) at 125°C was in the range 1.3-1.6. The average field acceleration parameter was ~8.67 cm/MV, and an effective dipole moment of bond breakage peff was ~29.73e Å. The thermochemical model (E model) suggested that the oxygen vacancies induced by the dipolar energy contribution (p · Eloc) easily caused bond breakage in the HK dielectric. The energy required to form another V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> was weakened to the bond strength of polar molecules. The characteristic breakdown strength (EBD) of ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> was 6.31 MV/cm, and the extracted activation energy AH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> * was 1.874 eV when considering E model.