抄録
It is anticipated that Pb(Zrx,Ti1-x)O3 (PZT) films will be used in various next-generation high performance devices, such as ferroelectric memories and microelectromechanical systems (MEMS). However, PZT films show degradation problems due to the presence of crystal defects. In order to solve this problem, it is necessary to elucidate the degradation mechanisms. In this paper, PZT films containing excess lead content at the interface between the electrode and the PZT layer were evaluated by thermally stimulated current measurements, which is one of the evaluation methods for crystal defects. Although, defects at the interface increased with increasing excess lead content, fatigue performance was reduced. The number of defects in usual PZT films increase due to fatigue, and inversely, a decrease in defects with progress of fatigue was also observed in the excess-lead film. Based on these results, a very thin excess PbOx layer containing crystal defects seems to exist at the interface, and compensates for the decrease in lead and oxygen content in the PZT layer by out-diffusion caused by fatigue.
