Switching and Fatigue Characteristics of (Pb, La)(Zr, Ti)O₃ Thin Films by Metalorganic Chemical Vapor Deposition

Abstract

Lanthanum-modified lead zirconate titanate (PLZT) thin films (0.3∼0.4 µm) have been prepared on Pt/SiO2/Si substrates at 650°C by the metal-organic chemical vapor deposition (MOCVD) method. The electrical properties of the films were examined as a function of lanthanum content. The relative dielectric constants increased as the La content increased to about 5 at%, and beyond this value, it became constant at 600. The remanent polarization and coercive field decreased from 22 to 1 µC/cm2 and from 90 to 20 kV/cm with increasing La content in the range of 0∼11 at%, respectively. The leakage current density decreased considerably with the addition of La, and was 8×10-9 A/cm2 at an applied voltage of 5 V. The switched charge densities of PLZT films showed almost no change up to switching cycles of 1×1012 at a bipolar pulse of ±5 V.

Effects of Nb doping on highly fatigue-resistant thin films of (Pb0.8Ba0.2)ZrO3 for ferroelectric memory application

“…The leakage current characteristic of the PBNZ films was then measured at room temperature. PBZ films which is in good agreement with the results of Nb-doped PZT films [14][15][16].…”

Effect of manganese doping on the size effect of lead zirconate titanate thin films and the extrinsic nature of ‘dead layers’

“…For example, doping could lead to enhanced fatigue resistance, 21,22 lowered leakage, smaller E c , 22 and so on. Surprisingly, the effects of doping on the issue of size effects have been rarely studied, and the current knowledge about this issue is very poor.…”

The Rise and Fall of Tetraethyllead. 2.

“…70 The volatility of tetraethyllead and its ready thermal decomposition to lead and organic products, factors important in its use as an antiknock agent in the gasoline engine, have also been useful in its application as a lead source in chemical vapor deposition of leadcontaining solid films for ferroelectric applications. Thus, films of lead titanate, PbTiO 3 , were prepared using a vapor reactant system of (C 2 H 5 ) 4 74 And now, toward the end, we come full circle and return to the beginning: to the discovery of the first organolead compounds by Carl Löwig in 1853. 2 In one of the first experiments that he described an ether solution of the liquid product of his reaction of ethyl iodide with sodium-lead alloy was allowed to evaporate partially in air, leaving an insoluble white precipitate.…”