Retention loss in the ferroelectric (SrBi2Ta2O9)-insulator (HfO2)-silicon structure studied by piezoresponse force microscopy
Institute of Modern Physics, Xiangtan University - Xiangtan 411105, Hunan, China
2 Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, Xiangtan University - Xiangtan 411105, Hunan, China
3 Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, Qingdao University Qingdao 266071, Shandong, China
Accepted: 27 March 2012
Metal-ferroelectric-insulator-silicon (MFIS) structures with SrBi2Ta2O9 as ferroelectric thin film and HfO2 as insulating buffer layer were fabricated by pulsed-laser deposition. The interfaces and memory window of the MFIS structure were investigated. Piezoresponse force microscopy was used to observe the change of domain images in order to investigate the retention characteristics, which demonstrated that the MFIS structure experiences retention loss via a random-walk–type process, identified by a stretched exponential-decay model. The corresponding mechanism was discussed based on the time-dependent depolarization field.
PACS: 77.84.-s – Dielectric, piezoelectric, ferroelectric, and antiferroelectric materials / 77.80.Dj – Domain structure; hysteresis / 77.80.Fm – Switching phenomena
© EPLA, 2012