Microstructure and Chemistry of Nonstoichiometric (Ba,Sr)TiO3 Thin Films Deposited by Metalorganic Chemical Vapor Deposition

2000 ◽  
Vol 15 (7) ◽  
pp. 1433-1436 ◽  
Author(s):  
Igor Levin ◽  
Richard D. Leapman ◽  
Debra L. Kaiser
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Grain Boundaries ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Significant Drop ◽  
Si Substrates ◽  
Ti Content ◽  
Metalorganic Chemical

The microstructure and chemistry of (Ba,Sr)TiO3 thin films deposited on Pt/SiO2/Si substrates by metalorganic chemical vapor deposition were studied using highresolution transmission electron microscopy and quantitative spectrum imaging in electron energy loss spectroscopy. The grain boundaries in all films with overall Ti content ranging from 50.7% to 53.4% exhibit a significant increase in Ti/Ba ratio as compared to the grain interiors. The results suggest that the deviations of Ti/(Ba + Sr) ratio from the stoichiometric value of unity are accommodated by the creation of Ba/Sr vacancies, which segregate to the grain boundary regions. The films with Ti contents equal to or greater than 52% additionally contained an amorphous Ti-rich phase at some grain boundaries and multiple grain junctions; the amount of this phase increases with increasing overall Ti content. The analysis indicates that the amorphous phase can only partially account for the significant drop in dielectric permittivity accompanying increases in the Ti/(Ba + Sr) ratio.

Processing Of PbTi03 And Pb(ZrxTi1−x)03 Thin Films By Novel Single-Solid-Source Metalorganic Chemical Vapor Deposition

1997 ◽  
Vol 474 ◽  
Author(s):  
Ping Lu ◽  
Hang Li ◽  
Shan Sun ◽  
Brace Tuttle
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Si Substrates ◽  
Process Reliability ◽  
Precursor Powders ◽  
Metalorganic Chemical

ABSTRACTFerroelectric PbTiO3(FT) and Pb(ZrxTi1−x)03 (PZT) thin films have been deposited on (100) MgO and (111) Pt/SiO2/(100)Si substrates by using a novel single-solid-source metalorganic chemical vapor deposition (MOCVD) technique. The new technique uses a powder delivery system to deliver the mixed precursor powders directly into a hot vaporizer from room temperature, therefore, avoiding any problems associated with polymerization or decomposition of the precursors before evaporation. The technique simplifies MOCVD processing significantly and can improve process reliability and reproducibility. The deposited FT and PZT films have a perovskite structure and are highly oriented with respect to the substrate. With improvement of process control, systematic studies of film evolution under various growth conditions have been carried out. Effects of substrate, substrate temperature, system vacuum, and precursor ratios in the mixture on film microstructure and properties will be presented in this paper.

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