Relationship Processing–Composition–Structure–Resistivity of LaNiO3 Thin Films Grown by Chemical Vapor Deposition Methods

Abstract

Precision control of resistivity/conductivity of LaNiO3 (LNO) films is essential for their integration as electrodes in the functional heterostructures. This becomes possible if the relationship between processing parameters–composition–structure–resistivity is determined. LaNiO3 films were deposited by three different chemical vapor deposition methods using different precursor supply systems: direct liquid delivery, pulsed liquid injection, and aerosol generation. The possibilities to ameliorate the efficiency of precursor evaporation and of film growth were studied. The relationship between deposition conditions and composition was determined. Detailed analysis of the epitaxial growth of LNO films on cubic and trigonal substrates and the influence of the rhombohedral distortion on the microstructural quality was done. The resistivity of LaNiO3 films, grown by chemical vapor deposition, was mainly defined by microstructural defects and La/Ni composition. The high epitaxial quality LaNiO3/LaAlO3 films with nearly stoichiometric La/Ni ratio presented low resistivity, which was very close to that of bulk LaNiO3. Their annealing in oxygen atmosphere had little effect on the resistivity, which suggests a minor presence of oxygen vacancies in the as-grown films.

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

“…These films did not relax completely to the bulk LaNiO 3 lattice parameters as a thinner film containing solely the 001 orientation. [46] Kuprenaite et al [80] used CVD reactors with three different precursor delivery systems, PI-MOCVD, atmospheric pressure MOCVD (AP-MOCVD), and a commercial direct liquid injection MOCVD, to study the effects of solvent, evaporation temperature, deposition pressure, growth temperature, and the relationship between film and solution compositions in order to optimize the composition and growth efficiency of LNO films in function of La and Ni β-diketonates. PI-MOCVD and AP-MOCVD methods employed monoglyme (1,2-dimethoxyethane) as solvent, and La(thd) 3 and Ni(thd) 2 as precursors.…”

“…Composition deviations from stoichiometry and microstructural flaws were the key determinants of resistivity in CVD-grown LNO films. [80] The used MOCVD techniques and the resultant characteristics for conducting perovskite thin films are summarized in Table 4. For the synthesis of conducting lanthanum manganites and cobaltites, such as LSMO, LMO, and LCO, metal β-diketonate precursors have been prevalently applied in the MOCVD processes.…”

“…Composition deviations from stoichiometry and microstructural flaws were the key determinants of resistivity in CVD‐grown LNO films. [ 80 ]…”

Morphological and Structural Evolution of Chemically Deposited Epitaxially LaNiO3 Thin Films

“…Through this synthesis route, the resistivity of the films was about 10 −4 Ω•cm. S. Kuprenaite et al [19] studied the growth of LaNiO 3 thin films using three different metal organic chemical vapor deposition methods on different substrates (0112) R-sapphire, (100) Si, and (0112) LaAlO 3 . In all three cases, "cube on cube" growth was dominant.…”

A foundation for complex oxide electronics -low temperature perovskite epitaxy

“…Techniques used for the deposition of epitaxial complex oxide systems include molecular beam epitaxy and pulsed laser deposition, neither of which is straightforward to implement in a production line due to high-temperature, highvacuum and limited area synthesis 22,23 . Chemical techniques like chemical vapor deposition (CVD) are also employed, but the resulting films require post-annealing at >600°C to obtain epitaxy 24,25 . This effectively hampers its applicability in monolithic device integration.…”