BaTiO3 Thin Films Prepared by Organometallic Chemical Vapor Deposition

1991 ◽  
Vol 243 ◽  
Author(s):  
L.A. Wills ◽  
B.W. Wessels ◽  
D.L. Schulz ◽  
T.J. Marks

AbstractBaTiO3 thin films have been prepared by low pressure organometallic chemical vapor deposition on (100) MgO and (100) LaAlO3 substrates using the volatile precursors, titanium(IV) tetraisopropoxide and barium (hexafluoroacetylacetonate)2 (tetraglyme). The phase composition and structure of the films depends on the reactant partial pressure, growth temperature, and substrate. High quality, epitaxial BaTiO3 films can be prepared in-situ on LaAlO3 as confirmed by x-ray diffraction measurements. These BaTiO3 films exhibit smooth surface morphologies as evidenced by scanning electron microscopy. Electrical resistivity measurements indicate that the films are semi-insulating.

1993 ◽  
Vol 335 ◽  
Author(s):  
Frank Dimeo ◽  
Bruce W. Wessels ◽  
Deborah A. Neumayer ◽  
Tobin J. Marks ◽  
Jon L. Schindler ◽  
...  

AbstractBi2Sr2CaCu2O8 thin films have been prepared in situ by low pressure metalorganic chemical vapor deposition using fluorinated β–diketonate precursors. The influence of the growth conditions on the oxide phase stability and impurity phase formation was examined as well as the superconducting properties of the films. Thin films deposited on LaAIO3 substrates were epitaxial as confirmed by x-ray diffraction measurements, including θ-2θ and φ scans. Four probe resistivity measurements showed the films to be superconducting with a maximum Tc0 of 90 K without post annealing. This Tc0 is among the highest reported for thin films of the BSCCO (2212) phase, and approaches reported bulk values.


1991 ◽  
Vol 6 (9) ◽  
pp. 1913-1918 ◽  
Author(s):  
Jiong-Ping Lu ◽  
Rishi Raj

Chemical vapor deposition (CVD) of titanium oxide films has been performed for the first time under ultra-high vacuum (UHV) conditions. The films were deposited through the pyrolysis reaction of titanium isopropoxide, Ti(OPri)4, and in situ characterized by x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). A small amount of C incorporation was observed during the initial stages of deposition, through the interaction of precursor molecules with the bare Si substrate. Subsequent deposition produces pure and stoichiometric TiO2 films. Si–O bond formation was detected in the film-substrate interface. Deposition rate was found to increase with the substrate temperature. Ultra-high vacuum chemical vapor deposition (UHV-CVD) is especially useful to study the initial stages of the CVD processes, to prepare ultra-thin films, and to investigate the composition of deposited films without the interference from ambient impurities.


1989 ◽  
Vol 169 ◽  
Author(s):  
J. M. Zhang ◽  
H. O Marcy ◽  
L .M. Tonge ◽  
B. W. Wessels ◽  
T. J. Marks ◽  
...  

AbstractFilms of the high‐Tc undoped and Pb‐doped Bi‐Sr‐Ca‐Cu‐O (BSCCO) superconductors have been prepared by low pressure organometallic chemical vapor deposition (OMCVD) using the volatile metal‐organic precursors Cu(acetylacetonate)2, Sr(dipivaloylmethanate)2, Ca(dipivaloylmethanate)2, and triphenyl bismuth. Factors which influence texture and morphology of the OMCVD‐derived films have been investigated, including the effects of annealing, doping, and substrates.


1989 ◽  
Vol 55 (18) ◽  
pp. 1906-1908 ◽  
Author(s):  
J. M. Zhang ◽  
H. O. Marcy ◽  
L. M. Tonge ◽  
B. W. Wessels ◽  
T. J. Marks ◽  
...  

1995 ◽  
Vol 10 (9) ◽  
pp. 2166-2169 ◽  
Author(s):  
Y.Q. Li ◽  
J. Zhang ◽  
S. Pombrik ◽  
S. DiMascio ◽  
W. Stevens ◽  
...  

A large magnetoresistance change (ΔR/RH) of −550% has been observed at 270 K in (La0.8Ca0.2)MnO3 thin films. The films were prepared in situ on LaAlO3 substrates by single-liquid-source metal-organic chemical vapor deposition. M(thd)n (M = La, Ca, and Mn, and n = 2, 3) were dissolved together in an organic solution and used as precursors for the deposition of (La0.8Ca0.2)MnO3 thin films. Deposition was conducted at an oxygen partial pressure of 1.2 Torr and a substrate temperature ranging from 600 °C to 700 °C. The mechanism for the large magnetoresistance change in this manganese oxide is briefly discussed.


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