Properties of Binary Si:H Materials Prepared by Hydrogen Plasma Sputtering

1989 ◽  
Vol 164 ◽  
Author(s):  
Shoji Furukawa ◽  
Tatsuro Miyasato

AbstractBinary Si:H materials are prepared by means of the rf sputtering technique in pure hydrogen atmosphere on low temperature (about 100 K) and room temperature substrates. The physical properties of the obtained materials are very much affected by the rf power and substrate temperature during the deposition. The material prepared at a low substrate temperature with a low rf power has a wide optical gap, and shows a visible photoluminescence at room temperature. On the other hand, the material prepared at room temperature with a high rf power contains many Si microcrystals, whose diameters are relatively large, and its optical gap becomes very small. The latter condition causes the dependence of the crystalline direction of the material film on the substrate crystal even at the room temperature. An rf power-modulated multi-layered structure (superlattice) is also proposed, and an apparent diffraction peak can be observed in the low-angle X-ray scattering measurement.

1986 ◽  
Vol 70 ◽  
Author(s):  
Mark L. Albers ◽  
H. R. Shanks ◽  
J. Shinar

ABSTRACTPreliminary results of a comparative study of some optical and ESR properties of aSi:H films prepared by rf sputtering on a cold substrate in 10 mtorr of either He, Ar, or Xe and 0.5 mtorr H2 are presented. In all cases the concentration of Si-H and Si-H2 bonds, the optical gap and the dangling bond spin density all generally increase as the rf power is decreased from 3.3 to 0.27 W/cm2. However, whereas the optical energy gap of He/H2 sputtered films ranges from 1.26 eV to 2.13 eV, the gap of Ar/H2 and Xe/H2 films sputtered under these conditions only changes from 1.54 to 1.94 and 1.41 to 1.71 eV, respectively. The dangling bond spin densities are lowest (~1017 cm-3) in the Ar/H2 sputtered films at high rf power and highest (~5x1018 cm-3) in Xe/H2 sputtered films at low power.


2005 ◽  
Vol 19 (30) ◽  
pp. 4437-4447 ◽  
Author(s):  
P. YANG ◽  
X. P. FENG ◽  
Y. C. SHI ◽  
Y. H. YAN ◽  
J. ZHANG

High N content of carbon nitride films are quickly deposited onto Si (100) substrates at room temperature by using DC hollow cathode plasma sputtering deposition technique. The deposition rate is up to 283 nm/min at the bias voltage of 400 V. The properties of the films are characterized by using XPS, Raman (scattering) and Fourier transformation infrared (FTIR) spectroscopy. Experiments results provide direct evidences that the structures of CN films can be controlled by regulating bias voltages. The maximum sp3 C – N concentration up to 0.73 is obtained. Raman data is used to confirm XPS results. FTIR of the films clearly show C – N and C = N components (1000–1800 cm-1) together with a tiny peak C ≡ N (2181 cm-1). By reducing particle energy and substrate temperature, we have succeeded in suppressing the mechanisms of losing N -contain species during deposition, and achieved a large amount of sp3 bonds of CN films.


2002 ◽  
Vol 746 ◽  
Author(s):  
Tatsuo Fujii ◽  
Makoto Sadai ◽  
Masakazu Kayano ◽  
Makoto Nakanishi ◽  
Jun Takada

ABSTRACTEpitaxial thin films of (001)-oriented FeTiO3+δ were prepared on α-Al2O3(001) single crystalline substrates by helicon plasma sputtering technique. The FeTiO3+δ films had large oxygen nonstoichiometry, which seriously depended on both substrate temperature and oxygen pressure during the sputtering deposition. The valence states of Fe ions in FeTiO3+δ changed monotonically from Fe2+ to Fe3+ with decreasing the substrate temperature from 900 to 400°C or with increasing the oxygen pressure from 0.9 to 1.8×10-6 Pa. The change of Fe valence states from Fe2+ to Fe3+ induced the magnetic phase transition only for the films prepared at 900°C. The films containing Fe2+ were paramagnetic while those with Fe3+ were antiferromagnetic at room temperature. The oxygen nonstoichiometry of the FeTiO3+δ films was probably produced by cation vacancies and disarrangement of Fe3+ and Ti4+ ions, which randomly occupied both interstitial and substitutional sites of the FeTiO3 related structure.


1987 ◽  
Vol 99 ◽  
Author(s):  
Paul H. Ballentine ◽  
A. M. Kadin ◽  
J. Árgana ◽  
R. C. Rath

ABSTRACTThin films of Y-Ba-Cu-O have been prepared by rf diode sputtering from a single mixed-oxide powder target. The films were deposited on sapphire and cubic zirconia substrates, with the substrates either cooled, heated, or left to establish thermal equlibrium. The Cu content in the films decreased with increasing substrate temperature. Films having composition close to the desired 1–2–3 stoichiometry were fabricated either by enriching the target with CuO or by cooling the substrate. Using the latter approach, a single target was used for over 20 depositions yielding films that were uniform in composition (although slightly Cu-rich), and consistent from run to run. These films had as-deposited room temperature sheet resistances on the order of 100 kΩ. Subsequent annealing at temperatures up to 850 C resulted in films that were superconducting with an onset around 90 K and zero resistance at 50 K. The critical current was found to exceed 2000 A/cm2 at 4.2 K.


2005 ◽  
Vol 900 ◽  
Author(s):  
Chien-Sheng Huang ◽  
Bohr-Ran Huang ◽  
Yung-Huang Jang ◽  
Meng-Shian Tsai ◽  
Jiun-You Ya ◽  
...  

ABSTRACTCarbon nanotubes (CNTs) were synthesized by thermal chemical vapor deposition (thermal CVD) on n-type Si (100) at 700 ° under C2H2 gas flow ratio of 30 sccm. Fe catalysts were pre-deposited by RF sputtering system with RF power 150 W. Two kinds of as-grown CNTs were used to detect N2: the vertically oriented carbon nanotubes (CNTs) mat and horizontally oriented CNTs bundle. Two-terminal electrical measurements were performed at room temperature of 25 °. The electrical resistance of CNTs mat or bundle was found to increase when exposed to N2 environment, and to return back after the N2 pumping, respectively. However, the CNTs bundle had better sensitivity and possessed faster response and recovery time. This could be ascribed to that the CNTs bundle, with more effective grooves on the surface, provided more lower binding-force sites to absorb N2 molecules than the CNTs mat dose, which prominently had interstitial sites.


1999 ◽  
Vol 14 (4) ◽  
pp. 1658-1663
Author(s):  
J. H. Je ◽  
H. K. Kim ◽  
D. Y. Noh

The microstructure of the amorphous, silicide, and crystalline Fe films grown on Si(001) substrates by a radio-frequency (rf) magnetron sputtering was studied in synchrotron x-ray scattering experiments. During the growth, iron-silicide interlayers were always formed. The silicide interlayer became crystalline β–FeSi2 at high rf power (⩾20 W/cm2) and at the substrate temperature of 100 °C. The formation of the β–FeSi2 was also promoted by postannealing to 300 °C. The Fe films grown on top of the silicide interlayer were amorphous at low substrate temperatures (⩽100 °C). It became crystalline only at high substrate temperature (300 °C) with the low rf power of 2 W/cm2. The crystalline Fe film was nonepitaxial but had the [111] preferred orientation.


1992 ◽  
Vol 270 ◽  
Author(s):  
G. Amato ◽  
G. Benedetto ◽  
L. Boarino ◽  
F. Demichelis ◽  
C. F. Pirri ◽  
...  

ABSTRACTDiamond-like amorphous carbon and hydrogenated amorphous carbon films (DLC) prepared by rf sputtering have been characterized by means of measurements of optical gap, hardness and Young's modulus. Preliminary results of the application of the photothermal displacement technique (PTD) are also reported, confirming that this method can in principle be applied for a more complete characterization of DLC films at room temperature and low temperatures.


Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.


2019 ◽  
Vol 7 (17) ◽  
pp. 10696-10701 ◽  
Author(s):  
Fábio G. Figueiras ◽  
J. Ramiro A. Fernandes ◽  
J. P. B. Silva ◽  
Denis O. Alikin ◽  
Eugénia C. Queirós ◽  
...  

Thriving ferroelectric oxide Bi2ZnTiO6 thin films with a 1.48 eV optical gap.


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