Deposition mechanism of nanostructured thin films from tetrafluoroethylene glow discharges

2005 ◽  
Vol 77 (2) ◽  
pp. 399-414 ◽  
Author(s):  
A. Milella ◽  
F. Palumbo ◽  
P. Favia ◽  
G. Cicala ◽  
R. d’Agostino
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Water Repellency ◽  
High Water ◽  
Experimental Conditions ◽  
Deposition Mechanism ◽  
Force Microscopy ◽  
Glow Discharges ◽  
Atomic Force ◽  
Surface Migration

Nanostructured polytetrafluoroethylene (PTFE)-like thin films can be deposited, in certain experimental conditions, by modulated discharges fed with tetrafluoroethylene (TFE). These coatings are characterized by a unique morphology consisting of highly twisted micron-long ribbons, which leads to an extremely high water repellency of the surface. In the present work, the diagnostics of the plasma phase is presented, coupled with that of the coating, in order to understand the film growth mechanism in different discharge regimes. When the duty cycle (DC) is increased in modulated C2F4 plasmas, the monomer depletion increases, too, and many recombination reactions take place at progressively higher rates, resulting in the formation of CF4, C2F6, C3F6, C3F8, and C4F10; the formation of powders in the homogeneous phase, however, was never evidenced. The modulation of C2F4 plasmas strongly affects the morphology of the resulting coating, as revealed by atomic force microscopy (AFM), ranging from bumpy to ribbon-like structures. The latter, moreover, are found to be more PTFE-like with respect to the remaining part of the film. In the last part of the paper, a deposition mechanism is proposed, where low radical densities in the plasma and surface migration of the precursors are the keys for the growth of ribbon-like structures.

YBCO film growth on ultrathin Ag layers

1994 ◽  
Vol 9 (11) ◽  
pp. 2761-2763 ◽  
Author(s):  
C. Zhong ◽  
S.T. Ruggiero ◽  
R. Fletcher ◽  
E. Moser
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Film Growth ◽  
Ybco Film ◽  
Critical Currents ◽  
Complete Coverage ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sputter Deposited ◽  
Marked Tendency

We discuss our results on the growth of YBCO thin films on ultrathin (1-10 nm) Ag underlayers. Substrates were LaAlO3. YBCO was sputter deposited and Ag thermally evaporated. It was observed that Tc remained relatively unaffected by the Ag underlayers, ranging from 86-88 K. Critical currents were found to be consistent with YBCO grown on bulk Ag when the Ag underlayer film reached complete coverage (∼9 nm). Films grown on Ag showed a marked tendency for microcrystalline growth on the basis of atomic-force microscopy (AFM) results.

scholarly journals Chemical bath deposition of textured and compact zinc oxide thin films on vinyl-terminated polystyrene brushes

2016 ◽  
Vol 7 ◽  
pp. 102-110 ◽  
Author(s):  
Nina J Blumenstein ◽  
Caroline G Hofmeister ◽  
Peter Lindemann ◽  
Cheng Huang ◽  
Johannes Baier ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Polymer Brush ◽  
Oriented Attachment ◽  
Zno Films ◽  
Island Growth ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Before And After

In this study we investigated the influence of an organic polystyrene brush on the deposition of ZnO thin films under moderate conditions. On a non-modified SiO x surface, island growth is observed, whereas the polymer brush induces homogeneous film growth. A chemical modification of the polystyrene brushes during the mineralization process occurs, which enables stronger interaction between the then polar template and polar ZnO crystallites in solution. This may lead to oriented attachment of the crystallites so that the observed (002) texture arises. Characterization of the templates and the resulting ZnO films were performed with ζ-potential and contact angle measurements as well as scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). Infrared spectroscopy (IR) measurements were used to investigate the polystyrene brushes before and after modification.

scholarly journals Sized WS2 Lamellae and their Texture Orientations Growth

2014 ◽  
Vol 11 (2) ◽  
pp. 98-101
Author(s):  
Khalil El-Hami ◽  
Cristina Louro ◽  
Albano Cavaleiro
Keyword(s):  
Thin Films ◽  
Solid Lubricant ◽  
Steel Substrate ◽  
Substrate Type ◽  
Experimental Conditions ◽  
Geometrical Size ◽  
Force Microscopy ◽  
Dc Sputtering ◽  
Atomic Force ◽  
Afm Analysis

The tungsten disulfide (WS2) thin films, considered as inert, non-toxic, non-corrosive lubrication that is resistant to most fuel solvents, is the best solid lubricant for general industry. In this paper, WS2 thin films were deposited on steel and silicon <110> type substrates by DC sputtering methods with optimized experimental conditions and parameters. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were employed to characterize the surface morphology and determine the geometrical size of WS2 lamellae or microtubes. The investigation showed that both SEM and AFM analysis revealed oriented WS2 crystalline lamellae on silicon substrate while they are entangled on the steel substrate. This result leads to say precociously that the WS2 thin films deposition depend on the substrate type. Moreover, using the AFM results, we could determine the average lamella (or microtube) size which has from 200 nm to 500 nm in width and from 1mm to 1.5mm in length. The EDS tool allows attaining the composition of deposited WS2 where the tungsten and the disulfide represent about 40 and 55%, respectively.

Atomic force microscopic studies of oxide thin films on organic self-assembled monolayers

1999 ◽  
Vol 14 (6) ◽  
pp. 2464-2475 ◽  
Author(s):  
T. P. Niesen ◽  
M. R. De Guire ◽  
J. Bill ◽  
F. Aldinger ◽  
M. Rühle ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Self Assembled Monolayers ◽  
Oxide Thin Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembled Monolayers ◽  
Microscopic Studies ◽  
Self Assembled ◽  
Attachment Mechanism

The surface morphology of TiO2- and ZrO2-based thin films, deposited from aqueous solution at 70–80 °C onto functionalized organic self-assembled monolayers (SAMs) on silicon has been examined using atomic force microscopy (AFM). The films have been previously shown to consist, respectively, of nanocrystalline TiO2 (anatase) and of nanocrystalline tetragonal ZrO2 with amorphous basic zirconium sulfate. The films exhibit characteristic surface roughnesses on two length scales. Roughness on the nanometer scale appears to be dictated by the size of the crystallites in the film. Roughness on the micron scale is postulated to be related to several factors, including the topography of the SAM and the effects of larger, physisorbed particles or agglomerates. The topographies of the oxide thin films, on both the nanometer and micron scales, are consistent with a particle-attachment mechanism of film growth.

Novel protein-repellent and antimicrobial polysaccharide multilayer thin films

Holzforschung ◽  
2018 ◽  
Vol 73 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Matea Korica ◽  
Lidija Fras Zemljič ◽  
Matej Bračič ◽  
Rupert Kargl ◽  
Stefan Spirk ◽  
...  
Keyword(s):  
Thin Films ◽  
Antibacterial Properties ◽  
Value Added ◽  
Medical Application ◽  
High Water ◽  
Regenerated Cellulose ◽  
Force Microscopy ◽  
Atomic Force

Abstract Nanostructured and bio-active polysaccharide-based thin films were manufactured by means of subsequent spin-coated deposition of a regenerated cellulose (RC) layer and a 2,2,6,6-Tetramethylpiperidine-1-oxyl radical (TEMPO) oxidised cellulose nanofibril (TOCN) layer. The bio-activity of the bilayer was achieved by addition of chitosan (CS). The chitosan was either mixed with the TOCN (TOCN+CS) and deposited on the RC layer by spin-coating, or deposited on the RC and TOCN bilayer by pumping its aqueous solution with various pH over the surface of the bilayer. The water content of the thin films and the CS interactions with the bilayer during deposition were studied in situ by means of a quartz crystal microbalance with dissipation (QCM-D). The pH dependent charging behaviour of the TOCN, TOCN+CS and CS dispersions was evaluated by pH-potentiometric titrations. The surface morphology of the thin films was characterised by atomic force microscopy (AFM). The bio-activity of the thin films was evaluated by studying their protein-repellent properties in situ with a continuous flow of bovine serum albumin (BSA) by means of QCM-D and by evaluating their antibacterial properties in vitro against Staphylococcus aureus and Escherichia coli. These polysaccharide-based thin films are high value-added products because of their multifunctionality, high water absorbance capacity, protein-repellence and antimicrobial activity, and have the potential for medical application as a wound dressing material.

Structural Control of Epitaxially Grown Sputtered Perovskite Thin Films

1995 ◽  
Vol 401 ◽  
Author(s):  
Kiyotaka Wasa ◽  
Toshifumi Sato ◽  
Hideaki Adachi ◽  
Kentaro Setsune ◽  
S. Trolier-McKinstry ◽  
...  
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Structural Control ◽  
Film Growth ◽  
Substrate Surface ◽  
Epitaxial Films ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force

AbstractThin films of perovskite Pb–Ti–O3 families were heteroepitaxially grown by sputtering on (0001)sapphire and/or (001)SrTiO (ST). These epitaxial films contained microstructures, although X–ray diffraction analysis suggested formation of single crystal phase with three dimentional crystal orientation. Their microstructures were studied by the electron microscopy, atomic force microscopy, and spectroscopic ellipsometry so as to find factors which influence the formation of the microstructure. It was found that the orientation of the substrate surface and the chemical composition of adatoms during initial film growth strongly affected the formation of the microstructures. Sputtered PbTiO3 (PT) thin films under a stoichiometric condition on a miscut(001) ST(miscut 1.7 degree) realized the growth of continuous single crystal thin films of 10–100nm thick with extremely smooth surface with surface roughness less than 3nm. Deposition on a miscut substrate under a stoichiometric condition is essential to make continuous thin films of perovskite of single crystal phase.

Structural, morphological, and optoelectrical characterization of Bi2S3 thin films grown by co-evaporation

2016 ◽  
Vol 30 (06) ◽  
pp. 1650066 ◽  
Author(s):  
F. Mesa ◽  
C. A. Arredondo ◽  
W. Vallejo
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Experimental Conditions ◽  
Soda Lime Glass Substrate ◽  
Text Type ◽  
Force Microscopy ◽  
Atomic Force

This work presents the results of synthesis and characterization of polycrystalline [Formula: see text]-type Bi2S3 thin films. The films were grown through a chemical reaction from co-evaporation of their precursor elements in a soda-lime glass substrate. The effect of the experimental conditions on the optical, morphological structural properties, the growth rate, and the electrical conductivity [Formula: see text] was studied through spectral transmittance, X-ray diffraction (XRD), atomic force microscopy (AFM) and [Formula: see text] versus [Formula: see text] measurements, respectively. The results showed that the films grow only in the orthorhombic Bi2S3 bismuthinite phase. It was also found that the Bi2S3 films present an energy band gap [Formula: see text] of about 1.38 eV. In addition to these results, the electrical conductivity of the Bi2S3 films was affected by both the transport of free carriers in extended states of the conduction band and for variable range hopping transport mechanisms, each one predominating in a different temperature range.

Atomic force microscopy of in situ deformed nickel thin films

1999 ◽  
Vol 353 (1-2) ◽  
pp. 194-200 ◽  
Author(s):  
C. Coupeau ◽  
J.F. Naud ◽  
F. Cleymand ◽  
P. Goudeau ◽  
J. Grilhé
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Force Microscopy ◽  
Nickel Thin Films ◽  
Atomic Force

scholarly journals Influence of Substrate Materials on Nucleation and Properties of Iridium Thin Films Grown by ALD

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 173
Author(s):  
Paul Schmitt ◽  
Vivek Beladiya ◽  
Nadja Felde ◽  
Pallabi Paul ◽  
Felix Otto ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Bulk Material ◽  
Atomic Layer ◽  
Substrate Material ◽  
Fused Silica ◽  
Silicon Wafers ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Influence Of Substrate

Ultra-thin metallic films are widely applied in optics and microelectronics. However, their properties differ significantly from the bulk material and depend on the substrate material. The nucleation, film growth, and layer properties of atomic layer deposited (ALD) iridium thin films are evaluated on silicon wafers, BK7, fused silica, SiO2, TiO2, Ta2O5, Al2O3, HfO2, Ru, Cr, Mo, and graphite to understand the influence of various substrate materials. This comprehensive study was carried out using scanning electron and atomic force microscopy, X-ray reflectivity and diffraction, four-point probe resistivity and contact angle measurements, tape tests, and Auger electron spectroscopy. Within few ALD cycles, iridium islands occur on all substrates. Nevertheless, their size, shape, and distribution depend on the substrate. Ultra-thin (almost) closed Ir layers grow on a Ta2O5 seed layer after 100 cycles corresponding to about 5 nm film thickness. In contrast, the growth on Al2O3 and HfO2 is strongly inhibited. The iridium growth on silicon wafers is overall linear. On BK7, fused silica, SiO2, TiO2, Ta2O5, Ru, Cr, and graphite, three different growth regimes are distinguishable. The surface free energy of the substrates correlates with their iridium nucleation delay. Our work, therefore, demonstrates that substrates can significantly tailor the properties of ultra-thin films.

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