Fatigue and dielectric properties of the (Pb, La)TiO3 thin films with various La concentrations

Fatigue and dielectric properties of the PLT thin films have been studied w ith varying the La concentration. The fatigue and the dielectric properties improve remarkably with the increase of La concentration from 5 to 28 mol% . In particular, after applying 10(9) square pulses with +/-5 V, the remane nt polarization of the PLT(10) thin film decreases only approximately 20% f rom the initial state while that of the PLT(5) thin film decreases as much as 70%. As the La concentration increases from 5 to 28 mol%, the dielectric constant at 10 kHz increases from 428 to 761, while the loss tangent and t he leakage current density at 150 kV/cm decreases from 0.063 to 0.024 and 6 .96 to 0.79 muA/cm(2), respectively. These results show that PLT(10) and PL T(28) thin films are potential candidates for the capacitor dielectrics of a new generation of NVFRAM and DRAM, respectively. (C) 2000 Elsevier Scienc e S.A. All rights reserved.