Novel Low Melting Point Barium and Strontium Precursors for the MOCVD Growth of Barium‐Strontium‐Titanate Films

Abstract

Novel barium and strontium precursors, belonging to the family of volatile complexes of the alkaline earth element (AEE) fluorinated b-diketonates with polyglymes, [M(dfhd) 2 (tetraglyme)] [Hdfnd ¼ 1,1,1,2,2,6,6,7,7,7-dekafluoro-heptane-3,5-dione, M ¼ Ba (I), Sr (II)], are synthesized and tested with an aim to use them for metal-organic (MO)CVD of Ba x Sr 1-x TiO 3 (BST) thin films. The thermal behavior and composition of vapor phases for compounds I and II are studied by thermal analysis and mass spectrometry (MS). Considerable reduction of the melting point (down to 80-90 8C) for both compounds I and II, as compared to known volatile complexes, is achieved. By means of the developed precursors, epitaxial BST films (x ¼ 0.5) are grown on SrTiO 3 substrates by using the modified MOCVD facility. The quality of the grown films is examined by high-resolution (HR) X-ray diffraction (XRD) and high-resolution (HR) scanning electron microscopy (SEM).

Metal–Organic Derivatives with Fluorinated Ligands as Precursors for Inorganic Nanomaterials

“…Thus, using the low-melting [M(dfhd) 2 (tetraglyme)] (M = Sr, Ba) as liquid delivery precursors, and Ti(OPr i ) 4 as the source for the titanium, the Ba x Sr 1−x TiO 3 (BST) films of 0.2−1 μm thickness were grown on the SrTiO 3 substrate. 328 The substrate temperature had a drastic effect on the crystalline quality of the grown films, and the best crystalline quality was obtained at 740 °C. Similarly, porous La 0.8 Sr 0.2 MnO 3 (LSMO) films for solid oxide fuel cell (SOFC) applications were deposited on yttria-stabilized zirconia (YSZ) using a molten mixture c o n s i s t i n g o f t h e [ L a ( h f a c ) 3 ( d i g l y m e ) ] , [ S r -(hfac) 2 (tetraglyme)], and [Mn(thd) 3 ] precursors by MOCVD technique.…”

Metal‐Organic Chemical Vapor Deposition of Oxide Perovskite Films: A Facile Route to Complex Functional Systems

“…Perovskite oxides such as CaCu 3 Ti 4 O 12 (CCTO), [40] BaTi (1-x) Zr x O 3 (BTZ), [41,42] SrTiO 3 , [43] LaAlO 3 , [44] and Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) [45] have also been synthesized as thin films through MOCVD on single-crystal substrates to be exploited in various microelectronic and optoelectronic fields due to their high dielectric constant (ε) values.…”

Ferroelectric and Dielectric Properties of Strontium Titanate Doped with Barium

“…BaSrTiO 3 (BST) has attracted considerable research interest, due to its strong dielectric nonlinearity under a bias electric field and linearly adjustable Curie temperature with the (Sr) content [3][4][5]. The extension of (Sr) into BaTiO 3 changes the Curie point to make BST a paraelectric material at room temperature, offering a high dielectric constant and low leakage current.…”