Field cycling behavior and breakdown mechanism of ferroelectric Al <sub>0.78</sub> Sc <sub>0.22</sub> N films
Sung‐Lin Tsai, Takuya Hoshii, Hitoshi Wakabayashi, Kazuo Tsutsui, Tien‐Kan Chung, Edward Yi Chang, Kuniyuki Kakushima
Abstract
Abstract The effects of field cycling of Al 0.78 Sc 0.22 N capacitors on ferroelectric properties are investigated. In the first hundreds of switching cycles, the reduction in the switching voltage was observed, possibly due to the formation of nitrogen-vacancy to facilitate the atom displacements. With further switching cycles, fatigue effect was observed, especially for domains with low switching voltage. The leakage current analysis indicates continuous downward band bending with the number of switching cycles, effectively reducing the Schottky barrier height for electrons. The breakdown of Al 0.78 Sc 0.22 N films is triggered by the Joule heat due to excessive leakage current. The mechanism is in contrast to conventional ferroelectric materials, where the breakdown is triggered by Joule heat at the local conductive filaments.