Enhanced fatigue property through the control of interfacial layer in Pt/PZT/Pt structure

Ferroeletric Pb(ZrxTi1-x)O3 PZT thin film capacitors with Pt(111)/SiO2/Si substrate were fabricated by sol-gel method. Ultrathin PZT layer containing various contents of excess Pb was adopted as an interfacial layer to investigate the role of excess Pb on the formation of interfacial region between PZT film and Pt bottom electrode. An improvement of electrical properties was observed according to the content of excess Pb in interfacial PZT layer due to the inhibition of inter-diffusion at film-substrate interface as well as defect formation. The formation of Ti-rich PZT at the initial stage of anneal due to excess Pb was responsible for the excellent ferroelectric characteristic. This implied that the role of excess Pb in film-substrate interface was of significance to the long-term reliability.