Thickness dependence of the ferroelectric characteristics of SBT and SBTN thin films

Abstract

SrBi2,4Ta,09 (SBT) and SrBiz,,(T~,,,Nbo,z5)Z09 (SBTN) thin films were prepared using LSMCD and MOD processes, respectively, and their fenoelectric properties were characterized with variation of the film thickness. The LSMCD-derived SBT film of 70 nm thickness exhibited the ?P, of 15.9 pC/cm2 and E, of 69 LV/cm at t 5 V. Within the thickness range of 70-410 nm, the SBT and SBTN films exhibited the size effects. i.e., a decrease of the remanent polarization and the relative permittivity and an increace of the coercive field with a reduction of the film thickness. The SBT and SBTN films of 70-410 nm thickness exhibited the fatigue-free behavior up to 10" switching cycles.

The Imidazole Role in Strontium β-Diketonate Complexes Formation

“…There is a growing interest in the chemistry of the alkaline-earth metal ions, particularly in the research area of strontium-based materials in the form of thin films. This is due to several possible applications in luminescent and electronic devices. , For example, Ln-doped strontium sulfide and Sr-containing fluoride glasses, such as SrAlF 5 , show interesting electroluminescent and optical features, − whereas SrTiO 3 and Bi−Sr−Ca−Cu or Sr−Bi−Ta mixed oxides are of interest for their applications respectively as high-K materials in DRAMs, − as HTSC materials, , and as ferroelectric nonvolatile random access memories FeRAM. , Among several techniques used to synthesize them, probably the most viable route for industry seems to be metal−organic chemical vapor deposition (MOCVD) because of the superior step coverage compared to other deposition techniques . Several strontium diketonates have been proposed as molecular precursors for MOCVD.…”

Kinetics and Mechanisms of MOCVD Processes for the Fabrication of Sr-Containing Films From Sr(hfac)2Tetraglyme Precursor

“…Thus, transparent Sr-containing fluoride glasses (such as SrAlF 5 ) have a key role for optical coatings and luminescent devices − and strontium titanates are of interest for their applications as high-K materials in DRAMs, − while Ln-doped Sr sulfide and Bi−Sr−Ca−Cu mixed oxides 19 are efficient materials for electroluminescent devices and superconducting electronics, respectively. Particular attention has recently been devoted also to SrBi 2 Ta 2 O 9 (SBT) ferroelectric oxides due to the great potentiality for ferroelectric nonvolatile random access memories (FeRAM). − SBT films can be fabricated through several techniques including pulsed laser deposition, , sol−gel, , metal−organic deposition, − and metal−organic chemical vapor deposition (MOCVD). − Among them, MOCVD appears the most viable route for the semiconductor industry because of the superior step coverage compared to that of other deposition techniques.…”