Production of Ultra-Thin Metal Films Using Neutral Cluster Beams

1990 ◽  
Vol 206 ◽  
Author(s):  
A. Ramachandra ◽  
M. Vaziri ◽  
R.P. Andres
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Vacuum Chamber ◽  
Metal Films ◽  
Gold Clusters ◽  
Cluster Beam ◽  
Neutral Cluster ◽  
Finite Electrical Conductivity ◽  
Cluster Beams

ABSTRACTGold clusters (diam. = 1.0 ± .5 nm) are prepared in a gas aggregation source (MECS), expanded into a vacuum chamber to form a neutral cluster beam, and deposited at low impact velocity on room temperature substrates. When several monolayers of these clusters are deposited on clean substrates (nitrocellulose, glass, mica, NaCl), they form smooth ultra-thin films. These cluster-assembled films appear to be similar in quality to those produced by the Takagi-Yamada ion cluster beam process. They exhibit finite electrical conductivity at thicknesses much smaller than is the case with atomically evaporated films. They are extremely uniform and smooth with a surface height that typically varies less than 1 nm across the entire film.

Supersonic Cluster Beam Synthesis of Nanophase Materials

1999 ◽  
Vol 581 ◽  
Author(s):  
P. Milanil ◽  
S. Iannotta ◽  
F. Biasioli ◽  
P. Piseri ◽  
E. Barborini
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Tini Alloy ◽  
Cluster Beam ◽  
Crystallite Sizes ◽  
Nanophase Materials ◽  
Cluster Beams ◽  
Cluster Beam Deposition ◽  
Beam Deposition

ABSTRACTWe present the characterization of supersonic cluster beam deposition as a viable technique for the synthesis of nanostructured materials. Stable and intense cluster beams can be obtained with a pulsed microplasma cluster source. This technique has been applied to produce TiNi nanostructured thin films on various substrates at room temperature. The morphology and the structure of the film are strongly influenced by the precursor clusters. Films characterized by crystallite sizes of a few tens of nanometers can be grown without recrystallization by thermal annealing. The stoichiometry of the original TiNi alloy is maintained.

Macromolecular structures of biological specimens are not obscured by controlled osmium impregnation

1983 ◽  
Vol 41 ◽  
pp. 606-607
Author(s):  
Klaus-Ruediger Peters ◽  
Samuel A. Green
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Critical Point ◽  
Metal Films ◽  
High Magnification ◽  
Osmium Impregnation ◽  
Instrumental Resolution ◽  
20 Nm ◽  
Continuous Metal

High magnification imaging of macromolecules on metal coated biological specimens is limited only by wet preparation procedures since recently obtained instrumental resolution allows visualization of topographic structures as smal l as 1-2 nm. Details of such dimensions may be visualized if continuous metal films with a thickness of 2 nm or less are applied. Such thin films give sufficient contrast in TEM as well as in SEM (SE-I image mode). The requisite increase in electrical conductivity for SEM of biological specimens is achieved through the use of ligand mediated wet osmiuum impregnation of the specimen before critical point (CP) drying. A commonly used ligand is thiocarbohvdrazide (TCH), first introduced to TEM for en block staining of lipids and glvcomacromolecules with osmium black. Now TCH is also used for SEM. However, after ligand mediated osinification nonspecific osmium black precipitates were often found obscuring surface details with large diffuse aggregates or with dense particular deposits, 2-20 nm in size. Thus, only low magnification work was considered possible after TCH appl ication.

Structure and Conductivity of Iodine-Doped C60 Thin Films

1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Thermally Activated ◽  
Order Of Magnitude

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

Electrical conductivity studies of mixed phthalocyanine thin films

Open Physics ◽  
2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Abraham Varghese ◽  
C. Menon
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Copper Phthalocyanine ◽  
Thermal Evaporation Technique ◽  
Nickel Phthalocyanine ◽  
Mixed Films ◽  
Evaporation Technique

AbstractThin films of mixed of Copper Phthalocyanine (CuPc) and Nickel Phthalocyanine (NiPc) are deposited onto a pure glass substrate by a simultaneous thermal evaporation technique at room temperature. The material D.C. electrical conductivity of films at room temperature and also films annealed at 523 K has been investigated. The optical absorption and band gaps of the films are also measured. The results show that the electrical resistance is lower for the mixed films compared with the pure samples and also the optical band gap decreases for the mixed samples compared to the pure samples.

Effects of Ionized Cluster Beam Bombardment on Epitaxial Metal Film Deposition on Silicon Substrates

1988 ◽  
Vol 128 ◽  
Author(s):  
Isao Yamada
Keyword(s):  
Room Temperature ◽  
Lattice Mismatch ◽  
Ion Beam ◽  
Substrate Surface ◽  
Metal Films ◽  
Epitaxial Films ◽  
Film Structure ◽  
Film Deposition ◽  
Cluster Beam ◽  
Tem Analysis

ABSTRACTThe effects of ion beam bombardment during ionized cluster beam (ICB) deposition of metal films on Si(111) and Si(100) substrates have been discussed. In the case of Al deposition, films have been epitaxially deposited on Si(lll) and Si(100) substrates at near room temperature. On Si(111) substrates, nearly perfect Al single crystal films could be formed. On Si(100) substrates, Al bicrystals have been grown epitaxially. A remarkable fact concerning these results is that the epitaxial films could be formed at nearly room temperature and on a large lattice mismatch (25%) substrate surface. Atomic resolution TEM analysis suggests that the epitaxy of Al occurs not only on Si surfaces but also at Al/Al grain boundaries. These epitaxial films exhibit extremely high thermal stability and long electromigration life time. To understand the deposition features and film characteristics, the effects of ICB bombardment on the film growth at the initial stage of the deposition and the resultant film structure have been studied. The results show that the role of very low energy ion bombardment is especially important in forming epitaxial metal films. Depositions of Au and Cu on Si substrates have also been made to understand whether ICB deposition may improve the characteristics of other metal films. Preliminary results of these film depositions are also obtained.

scholarly journals Rare Earth - Fe2 Thin Films Study With Strata™

1996 ◽  
Vol 4 (6) ◽  
pp. 22-23
Author(s):  
J. M. Claude ◽  
J. F. Thiot ◽  
V. Oderno ◽  
C. Dufour
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Room Temperature ◽  
Vacuum Chamber ◽  
High Vacuum ◽  
Growth Direction ◽  
Ultra High Vacuum ◽  
Laves Phases ◽  
20 Nm ◽  
The Rare Earth

The Rare-Earth Laves phases RE-Fe2 (RE represent the Rare-Earth) show large magnetostrictive properties, especially at room temperature. These materials are well characterized when in bulk form, but they have rarely been studied as thin films and one can expect some important effects due to epitaxial growth.A few single crystal layers of RE-Fe2 have been studied (YFe2, TbFe2, DyFe2, ErFe2: and Dy0.7Tb0.3Fe2 known as Terfenol-D). The thickness of these different layers are between 5 and 20 nm and with [110] as a growth direction have been epitaxied. They have been deposited with a Molecular Beam Epitaxy (MBE) in an ultra high vacuum chamber. A [1120] sapphire substrate is recovered by a [110] niobium buffer. The RE and the iron are then co-deposited on the substrate which is maintained at 500°C. Lastly, an Yttrium layer is deposited on the Rare Earth material at a temperature close to ambient.

Molybdenum doped Indium Oxide thin films prepared by rf sputtering

2005 ◽  
Vol 905 ◽  
Author(s):  
Elamurugu Elangovan ◽  
Antonio Marques ◽  
Ana Pimentel ◽  
Rodrigo Martins ◽  
Elvira Fortunato
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Indium Oxide ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Rf Sputtering ◽  
Electrical And Optical Properties ◽  
Volume Percentage ◽  
Annealing Conditions ◽  
Deposited Films

AbstractMolybdenum doped indium oxide (IMO) thin films rf sputtered at room temperature were studied as a function of oxygen volume percentage (O2 vol. %) varied between 0 and 17.5. The as-deposited films were amorphous irrespective of O2 vol. %. The minimum transmittance (<10 %) of the films deposited without oxygen has been increased on introducing oxygen (3.5 O2 vol. %) to a maximum of 90 %. The optical band gap has been increased from 3.80 eV (without oxygen) to 3.92 eV (3.5 O2 vol. %). The films were highly resistive and the hall coefficients were detectable only for the films deposited without oxygen. In order to increase the electrical conductivity, the films were annealed in the range 100-500°C in open-air and N2/H2 gas for 1 hour. The annealed films become polycrystalline with enhanced electrical and optical properties. The effect of annealing conditions on these films will be presented and discussed in detail.

Electrical Conductivity of SrRuO3 Thin Films Prepared by Laser Ablation

2005 ◽  
Vol 475-479 ◽  
pp. 1209-1212 ◽  
Author(s):  
Akihiko Ito ◽  
Hiroshi Masumoto ◽  
Takashi Goto
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Laser Ablation ◽  
Substrate Temperature ◽  
Room Temperature ◽  
High Vacuum ◽  
Amorphous Structure ◽  
Preparation Condition ◽  
Electrically Conductive

SrRuO3 (SRO) thin films were prepared by laser ablation. The optimum preparation condition of highly electrically conductive SRO thin films was investigated. The substrate temperature (Tsub) was changed from room temperature to 973 K, and the deposition atmosphere was at a high vacuum (P = 10-6 Pa) and in O2 at oxygen pressures (PO2) of 0.13 and 13 Pa. The films deposited at P = 10-6 Pa and PO2 = 0.13 Pa were amorphous structure. At Tsub > 573 K and PO2 = 13 Pa, well-crystallized pseudo-cubic SRO thin films with (110) orientation were obtained. With increasing Tsub, the conductivity of SRO films increased from 7.7×103 to 9.1×104 S·m-1. The epitaxially grown SRO films on (100) SrTiO3 substrates exhibited the highest conductivity of 1.8×105 S·m-1.

Novel Paths for Nucleatton and Growth of Thin Films by Ionized Cluster Beam (ICB) Techniques: Atomic-Scale Observations

1991 ◽  
Vol 235 ◽  
Author(s):  
I. Yamada ◽  
T. Yamada ◽  
G. H. Takaoka ◽  
H. Usui ◽  
M. I. Current
Keyword(s):  
Thin Films ◽  
Atomic Beam ◽  
Room Temperature ◽  
Film Growth ◽  
Atomic Scale ◽  
Cluster Beam ◽  
Film Properties ◽  
Early Stages ◽  
Detailed Composition ◽  
Large Clusters

ABSTRACTAtomic-scale observations by STM and TEM of the early stages of film growth and recent studies of the detailed composition of beams from ICB sources have led to new understandings of origins of some of the extraordinary properties of thin films deposited by ICB methods. The presence of a small fraction of atoms in the form of large clusters initiates a novel sequence of film growth steps starting with the immediate formation of stable islands for film growth. The growth of films from cluster-initiated islands leads to fundamentally altered film properties (compared to atomic beam, MBE, deposition) such as the epitaxial alignment of metal/semiconductor/ceramic multilayers grown near room temperature.

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