Dependences of Process-Induced Damage on Imprint Characteristics in SrBi₂Ta₂O₉ Capacitors

Abstract

We investigated hysteresis shifts in SrBi 2 Ta 2 O 9 capacitors during high-temperature storage in an attempt to understand the mechanism underlying imprint degradation. We found that the activation energy ( E a ) of imprint degradation is derived from the temperature dependence of the hysteresis shift, but is almost independent of the size of the capacitors (about 0.2 eV). On the other hand, E a is strongly dependent on the size of contact areas on the upper electrodes of the capacitors (0.1 to 0.2 eV). This result suggests that imprint degradation is mainly due to the characteristics of ferroelectric-electrode interfaces, and is not due to the edges of the capacitors. We reached this conclusion because the dependence on the contact areas is related to process-induced damage near the upper electrode.