Study on fatigue and breakdown properties of Pt/(Pb,Sr)TiO3/Pt capacitors

Abstract

Pulsed- laser deposited ( Pb, Sr) TiO3 ( PSrT) films on Pt/ SiO2/ Si substrate at various ambient oxygen pressures ( P-O2) are investigated in this work. Films deposited at P-O2 below 100 mTorr exhibit the ( 100) preferred orientation and a tetragonal structure with larger tetragonality. In addition, films deposited at 80 mTorr exhibit the most apparent ferroelectric properties in contrast to those deposited at 200 mTorr. Moreover, films deposited at higher P-O2 also exhibit longer lifetimes and higher breakdown fields due to their smaller leakage current density, in terms of the reduction of defects, compensation of oxygen vacancies (OVs), an improved interface and small cluster sizes. An energy band model reveals that fatigue properties of PSrT films are dominated by interfacial states at low P-O2 and by deep trapping states at high P-O2, which could be ascribed to OVs located at the interfaces and inside films, respectively.