Simultaneous Occurrence of Multiphases in the Interfacial Reactions of Ultrahigh Vacuum Deposited Ti, Hf and Cr Thin Films on (111)Si

1993 ◽  
Vol 311 ◽  
Author(s):  
W.W. Hsieh ◽  
J.J. Lin ◽  
M.M. Wang ◽  
L.L. Chen

ABSTRACTSimultaneous occurrence of multiphases was observed in the interfacial reactions of ultrahigh vacuum deposited Ti, Hf and Cr thin films on (111)Si by high resolution transmission electron microscopy in conjunction with fast Fourier transform diffraction analysis and image simulation. For the three systems, an amorphous interlayer as well as a number of crystalline phase were found to form simultaneously in the early stages of interfacial reactions. The formation of multiphases appeared to be quite general in the initial stages of interfacial reactions of UHV deposited refractory thin films. The results called for a reexamination of generally accepted “difference” in reaction sequence between bulk and thin film couples.

1991 ◽  
Vol 222 ◽  
Author(s):  
M. H. Wang ◽  
L. J. Chen

ABSTRACTThe initial stages of interfacial reactions of ultrahigh vacuum (UHV) deposited Ti thin films on silicon have been studied by in-situ reflected high energy electron diffraction (RHEED) and transmission electron microscopy (TEM).An amorphous interlayer was found to form during the deposition of the first 1.7-nm-thick Ti layer. In samples annealed at 450 °C for 30–120 min, Ti5Si3, located at the Ti/a-interlayer interface, was identified to be the first nucleated phase. Ti5Si3, Ti5Si4, TiSi and C49-TiSi2 were observed in samples annealed at 475 °C for 30 and 60 min as well as at 500 °C for 10 and 20 min. Fundamental issues in silicide formation are discussed in light of the discovery of the formation of the amorphous interlayer and as many as four different silicide phases in the initial stages of interfacial reactions of UHV deposited Ti thin films on silicon.


Author(s):  
J. L. Lee ◽  
C. A. Weiss ◽  
R. A. Buhrman ◽  
J. Silcox

BaF2 thin films are being investigated as candidates for use in YBa2Cu3O7-x (YBCO) / BaF2 thin film multilayer systems, given the favorable dielectric properties of BaF2. In this study, the microstructural and chemical compatibility of BaF2 thin films with YBCO thin films is examined using transmission electron microscopy and microanalysis. The specimen was prepared by using laser ablation to first deposit an approximately 2500 Å thick (0 0 1) YBCO thin film onto a (0 0 1) MgO substrate. An approximately 7500 Å thick (0 0 1) BaF2 thin film was subsequendy thermally evaporated onto the YBCO film.Images from a VG HB501A UHV scanning transmission electron microscope (STEM) operating at 100 kV show that the thickness of the BaF2 film is rather uniform, with the BaF2/YBCO interface being quite flat. Relatively few intrinsic defects, such as hillocks and depressions, were evident in the BaF2 film. Moreover, the hillocks and depressions appear to be faceted along {111} planes, suggesting that the surface is smooth and well-ordered on an atomic scale and that an island growth mechanism is involved in the evolution of the BaF2 film.


2003 ◽  
Vol 775 ◽  
Author(s):  
Donghai Wang ◽  
David T. Johnson ◽  
Byron F. McCaughey ◽  
J. Eric Hampsey ◽  
Jibao He ◽  
...  

AbstractPalladium nanowires have been electrodeposited into mesoporous silica thin film templates. Palladium continually grows and fills silica mesopores starting from a bottom conductive substrate, providing a ready and efficient route to fabricate a macroscopic palladium nanowire thin films for potentially use in fuel cells, electrodes, sensors, and other applications. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicate it is possible to create different nanowire morphology such as bundles and swirling mesostructure based on the template pore structure.


1996 ◽  
Vol 452 ◽  
Author(s):  
U. Klement ◽  
D. Horst ◽  
F. Ernst

AbstractThe objective of this work is to find a material to replace amorphous hydrogenated silicon used as photosensitive part in the “retina” of an “electronic eye”. For that reason, ZnS, ZnSe, CdS and CdSe were chosen for investigations. Thin films, prepared by chemical vapour deposition, were characterized by transmission electron microscopy. The observed microstructures were correlated with the optoelectronic properties of these materials. CdSe was found to be the most promising material for our application. Hence, the influence of a dielectric interlayer and the effects of additional annealing treatments were analyzed for CdSe and will be discussed with respect to the optimization of the material.


1990 ◽  
Vol 199 ◽  
Author(s):  
M. Libera ◽  
T. A. Nguyen ◽  
C. Hwang

ABSTRACTA number of techniques for producing TEM cross-sections of thin films have been described in recent years as the need for improved and more-thorough microstructural study of thin-film materials has grown. We have developed a method for producing such cross-sections which involves little sophisticated equipment other than an ion mill for thinning. Following the method of Bravman and Sinclair (J. Elec. Micrs. Tech 1,53–61 (1984)), the film of interest is either deposited on or epoxied to a silicon wafer and a composite of six silicon beams (=3mm × 25mm × 0.5mm) is fabricated. Slices are cut from this composite perpendicular to the film plane, and each slice is mechanically thinned by a series of simple grinding and polishing steps to ∼ 50–100μm. Dimpling is not necessary. The specimen is mounted onto a slotted TEM grid which provides a vehicle for safe handling, and the specimen is ion milled to perforation. We have found the technique to be relatively fast, reliable, and simple. Its success hinges on minimizing the amount of direct handling required when the specimen is thin and fragile. We present a detailed recipe describing its various steps and show typical results from studies of thin films for data-storage applications.


2013 ◽  
Vol 313-314 ◽  
pp. 254-257
Author(s):  
Ling Fang Jin ◽  
Hong Zhuang

Nonepitaxially grown FePt (x)/FePt:C thin films were synthesized, where FePt (x) (x=2, 5, 8, 11, 14 nm) layers were served as underlayers and FePt:C layer was nanocomposite with thickness of 5 nm. The effect of FePt underlayer on the ordering, orientation and magnetic properties of FePt:C thin films has been investigated by adjusting FePt underlayer thicknesses from 2 nm to 14 nm. X-ray diffraction (XRD), together with transmission electron microscopy (TEM) confirmed that the desired L10 phase was formed and films were (001) textured with FePt underlayer thickness decreased less 5 nm. For 5 nm FePt:C nanocomposite thin film with 2 nm FePt underlayer, the coercivity was 8.2 KOe and the correlation length of FePt:C nanocomposite film was 67 nm. These results reveal that the better orientation and magnetic properties for FePt:C nanocomposite films can be tuned by decreasing FePt underlayer thickness.


2000 ◽  
Vol 6 (S2) ◽  
pp. 462-463
Author(s):  
G. Y. Yang ◽  
V. Nagarajan ◽  
Z. L. Wang ◽  
Y. H. Li ◽  
R. Ramesh

Pb(Mg1/3Nb2/3)O3 (PMN)- and its solid solution with PbTiO3 (PT) is one of the lead-based relaxor ferroelectrics and has been the most widely studied materials because of their high dielectric constants and high electrostrictive coefficients. The potential impact of the thin film ferroelectric relaxors in the integrated actuators and sensing applications has stimulated research on the growth and characterization of thin films. Thin films have been made by pulsed-laser deposition (PLD), sol-gel and metalrganic chemical-vapor deposition. It is known that electrical properties may be strongly influenced by the microstructure of films and the interface structures between different phase in such heterostructure systems. In this paper, we report the investigation of interfacial mismatch and interface structure of epitaxial Pb(Mg1/3Nb2/3)O3 (90%)- PbTiO3 (10%) relaxor thin film by high resolution transmission electron microscopy (HRTEM).Thin film capacitors of Pb(Mg1/3Nb2/3)O3 (90%) - PbTiO3 (10%) (PMN-PT) were grown by PLD on (100)-oriented LaA1O3 (LAO) substrates. La0.5Sr0.5CoO3 (LSCO) layer was deposited as electrode. Cross-sectional transmission electron microscopy samples were prepared following the traditional procedures including cutting, gluing, polishing and ion milling.


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