A study of silicide formation from LPCVD-tungsten films: Film texture and growth kineticsa

1991 ◽  
Vol 6 (9) ◽  
pp. 1886-1891 ◽  
Author(s):  
S-L. Zhang ◽  
R. Buchta ◽  
M. Östling
Keyword(s):  
Chemical Vapor ◽  
Silicide Formation ◽  
X Ray Diffraction ◽  
Inexpensive Method ◽  
X Ray ◽  
Si Substrates ◽  
Kinetics Studies ◽  
Tungsten Hexafluoride ◽  
Pressure Chemical ◽  
History Of

Tungsten disilicide (WSi2) was formed by annealing tungsten (W) films of 330 nm and 750 nm prepared by low pressure chemical vapor deposition (LPCVD) from tungsten hexafluoride (WF6) on Czochralski 〈100〉-Si substrates. The silicide was found to grow continuously from the WSi2/W interface. The thickness of the formed WSi2 was observed by Rutherford backscattering measurements (RBS) to increase parabolically with the annealing time, with an activation energy of 2.6 eV/atom. The crystal structure of the formed WSi2 and the unreacted W films was analyzed using x-ray diffraction (XRD) technique. The thermal history of the samples was found to play an important role for the film texture of the unreacted W and formed WSi2, indicating that the fast and inexpensive method, XRD, applied as a thickness monitor for kinetics studies of WSi2 growth will undoubtedly introduce large errors. The as-deposited W (on Si) and the unreacted W (on WSi2) were found to be under a tensile stress, as observed by means of the XRD technique.

Hot-mesh Chemical Vapor Deposition for 3C-SiC Growth on Si and SiO2

2005 ◽  
Vol 862 ◽  
Author(s):  
Kanji Yasui ◽  
Jyunpei Eto ◽  
Yuzuru Narita ◽  
Masasuke Takata ◽  
Tadashi Akahane
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Mesh Structure ◽  
X Ray ◽  
Si Substrates ◽  
Substrate Temperatures ◽  
Sic Films

AbstractThe crystal growth of SiC films on (100) Si and thermally oxidized Si (SiO2/Si) substrates by hot-mesh chemical vapor deposition (HMCVD) using monomethylsilane as a source gas was investigated. A mesh structure of hot tungsten (W) wire was used as a catalyzer. At substrate temperatures above 750°C and at a mesh temperature of 1600°C, 3C-SiC crystal was epitaxially grown on (100) Si substrates. From the X-ray rocking curve spectra of the (311) peak, SiC was also epitaxially grown in the substrate plane. On the basis of the X-ray diffraction (XRD) measurements, on the other hand, the growth of (100)-oriented 3C-SiC films on SiO2/Si substrates was determined to be achieved at substrate temperatures of 750-800°C, while polycrystalline SiC films, at substrate temperatures above 850°C. From the dependence of growth rate on substrate temperature and W-mesh temperature, the growth mechanism of SiC crystal by HMCVD was discussed.

Assessment of Carbon Contamination in Titanium Nitride Films Deposited from the Reaction of Titanium (IV) Ciiloride and Amines

1993 ◽  
Vol 327 ◽  
Author(s):  
Keith B. Williams ◽  
Ogie Stewart ◽  
Gene P. Reck ◽  
James W. Proscia
Keyword(s):  
Titanium Nitride ◽  
Atmospheric Pressure ◽  
Chemical Vapor ◽  
Primary Amines ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
Carbon Contamination ◽  
X Ray ◽  
Infrared Reflectivity ◽  
Pressure Chemical

AbstractThe reaction of titanium (IV) chloride and amines in an atmospheric pressure chemical vapor deposition (APCVD) has been previously shown to produce high quality titanium nitride films. These films were gold in appearance with high infrared reflectivity and resistivities as low as 80 microhm-cm. In the present study, the carbon content of the amines was systematically increased and the carbon levels in the films measured by XPS. For primary amines carbon contamination was not detected. Films deposited from secondary and tertiary amines had measurable carbon contamination. Correlation of carbon contamination with electrical resistivity and infrared reflectivity is discussed. Scanning electron micrographs and x-ray diffraction of the films are presented.

Silicide Formation with Tungsten Deposited from W-LPCVD; The Role of Back Surface Conditions

1992 ◽  
Vol 260 ◽  
Author(s):  
S. -L. Zhang ◽  
M. Östling ◽  
U. Smith ◽  
R. Buchta
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Chemical Vapor ◽  
Front Surface ◽  
Back Surface ◽  
Surface Oxide Layer ◽  
Silicide Formation ◽  
Surface Conditions ◽  
Tungsten Hexafluoride ◽  
Pressure Chemical ◽  
Isothermal Heat Treatments

Tungsten (W) films were deposited on the front surface of float-zone (FZ) Si wafers, from tungsten hexafluoride (WF6) by low pressure chemical vapor deposition (LPCVD). The back surface conditions of the Si wafers was the major concern of this study. Various back surface coatings were investigated, tungsten, thermal SiO2 and LPCVD-Si3N4. Isothermal heat treatments were performed in an argon flow furnace at 760°C for 8 to 30 min. The silicide formation was monitored by Rutherford backscattering spectrometry (RBS). No difference in the silicidation rate was found on the wafers with a back surface oxide layer as compared to that of the reference wafers with no back surface coating. However, for wafers with the back surface covered with Si3N4 or W, a retarded silicidation rate was observed. This phenomenon appeared to be insensitive to the presence of a cap layer (PECVD-SiO2) on the W films before annealing. A model including the behavior of point defects is proposed to provide an explanation to this observation.

scholarly journals Ag-induced a New Raman Mode in ZnO Microrods

2019 ◽  
Vol 25 (3) ◽  
pp. 227-230
Author(s):  
Jing WANG ◽  
Lina WANG ◽  
Meina WANG ◽  
Dan ZHOU ◽  
Yan MEI ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Raman Mode ◽  
X Ray Diffraction ◽  
Characteristic Mode ◽  
Raman Analysis ◽  
X Ray ◽  
Ag Doping ◽  
Si Substrates ◽  
Hexagonal Shape ◽  
Vapor Deposition Technique

The chemical vapor deposition technique was used to prepare the Ag doped ZnO microrods, which were located on Si substrates at two different positions.  The scanning electron microscopy revealed that the samples have a clear hexagonal shape. X-ray diffraction provided information about the preferential orientation along the c-axis. The Raman analysis revealed that a new Raman mode appears at 492 cm-1 due to Ag doping. As this mode has not been reported early, it could be used as a characteristic mode of Ag doping in Raman spectrum. The red shift of the E2 (high) mode proves the existence of tensile stress in the samples. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19130

HETEROEPITAXIAL GROWTH AND ANNEALING OF γ-AL2O3 THIN FILMS ON SILICON

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4302-4305 ◽  
Author(s):  
LIWEN TAN ◽  
JUN WANG ◽  
QIYUAN WANG ◽  
YUANHUAN YU ◽  
LANYING LIN
Keyword(s):  
High Frequency ◽  
Chemical Vapor ◽  
High Energy ◽  
Annealing Effect ◽  
High Energy Electron ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pressure Chemical

The γ- Al 2 O 3 films were grown on Si (100) substrates using the sources of TMA ( Al ( CH 3)3) and O 2 by very low-pressure chemical vapor deposition (VLP-CVD). It has been found that the γ- Al 2 O 3 film has a mirror-like surface and the RMS was about 2.5nm. And the orientation relationship was γ- Al 2 O 3(100)/ Si (100). The thickness uniformity of γ- Al 2 O 3 films for 2-inch epi-wafer was less than 5%. The X-ray diffraction (XRD) and reflection high-energy electron diffraction (RHEED) results show that the crystalline quality of the film was improved after the film was annealed at 1000°C in O 2 atmosphere. The high-frequency C-V and leakage current of Al /γ- Al 2 O 3/ Si capacitor were also measured to verify the annealing effect of the film. The results show that the dielectric constant increased from 4 to 7 and the breakdown voltage for 65-nm-thick γ- Al 2 O 3 film on silicon increases from 17V to 53V.

Influence of Ammonia on the Fabrication of Aligned Carbon Nanotubes Using Thermal CVD

2011 ◽  
Vol 467-469 ◽  
pp. 312-315
Author(s):  
Gang Li ◽  
Wen Ming Cheng
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Vertical Alignment ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Aligned Carbon Nanotubes ◽  
20 Nm

Ultra-thin (20 nm) nickel catalyst films were deposited by sputtering on SiO2/Si substrates. At the pretreatments, ammonia (NH3) was conducted for different time in a thermal chemical vapor deposition (CVD) system. Pretreated samples were characterized using atomic force microscopy (AFM). After the pretreatment, acetylene was introduced into the chamber for 10 min, samples were characterized using scanning electron micrograph (SEM) and X-ray diffraction (XRD). It was concluded that NH3 pretreatment was very crucial to control the surface morphology of catalytic metals and thus to achieve the vertical alignment of carbon nanotubes (CNTs). With higher density of the Ni particles, better alignment of the CNTs can be obtained due to steric hindrance effect between neighboring CNTs.

Deposition and Properties of AlN Films Prepared by Low Pressure CVD with a Metalorganic Precursor

1993 ◽  
Vol 335 ◽  
Author(s):  
M. J. Cook ◽  
P. K. Wu ◽  
N. Patibandla ◽  
W. B. Hillig ◽  
J. B. Hudson
Keyword(s):  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Low Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fiber Coating ◽  
Pressure Chemical ◽  
Substrate Temperatures ◽  
Carbon Concentrations

AbstractAluminum nitride films were deposited on Si (100) and sapphire (1102) substrates by low pressure chemical vapor deposition using the metalorganic precursor trisdimethylaluminum amide, [(CH3)2AlNH2]3. Depositions were carried out in a cold wall reactor with substrate temperatures between 500 and 700 °C and precursor temperatures between 50 and 80 °C. The films were analyzed by X-ray photoelectron spectroscopy, X-ray diffraction, optical microscopy and scanning electron microscopy. The films were generally smooth and adherent with colors ranging from transparent to opaque grey. Cracking and spallation were seen to occur at high film thickness. Deposition rates ranged from 20 to 300 Å/min and increased with both precursor and substrate temperature. Carbon concentrations were small, < 5 at. %, while oxygen concentrations were higher and showed a characteristic profile versus depth in the film. High temperature compatibility testing with sapphire/AlN/MoSi2 samples was carried out to determine film effectiveness as a fiber coating in a composite.

Integration of GaAs on Ge/Si towers by MOVPE

2013 ◽  
Vol 1538 ◽  
pp. 283-289
Author(s):  
A. G. Taboada ◽  
T. Kreiliger ◽  
C. V. Falub ◽  
M. Richter ◽  
F. Isa ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Morphological Evolution ◽  
Chemical Vapor ◽  
Lattice Parameter ◽  
Low Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Organic Vapor ◽  
Metal Organic

ABSTRACTWe report on the maskless integration of micron-sized GaAs crystals on patterned Si substrates by metal organic vapor phase epitaxy. In order to adapt the mismatch between the lattice parameter and thermal expansion coefficient of GaAs and Si, 2 μm tall Ge crystals were first grown as virtual substrate by low energy plasma enhanced chemical vapor deposition. We investigate the morphological evolution of the GaAs structures grown on top of the Ge crystals at the transition towards full pyramids with energetically stable {111} facets. A substantial release of strain is shown in GaAs crystals with a height of 2 μm and lateral sizes up to 15×15 μm2 by both X-ray diffraction and photoluminescence.

Plasma Deposition of Tungsten

1986 ◽  
Vol 75 ◽  
Author(s):  
K. E. Greenberg
Keyword(s):  
Silicon Dioxide ◽  
Plasma Deposition ◽  
Chemical Vapor ◽  
Auger Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tungsten Hexafluoride ◽  
Aluminum Substrates ◽  
Deposited Film ◽  
Silicon Silicon

AbstractTungsten films were plasma-deposited using an abnormal glow discharge through a mixture of tungsten hexafluoride, hydrogen, and argon. The films adhered well to silicon, silicon dioxide, gallium arsenide, and aluminum substrates placed directly on the discharge cathode. Typical deposition rates were on the order of 160 Angstroms/minute with as-deposited film resistivities of 40 to 70 microohm-cm. The tungsten was analysed using a number of techniques including X-ray diffraction, scanning electron microscopy, and Auger spectroscopy, Low-resistivity (<10 microohm-cm) films that adhered well to silicon-dioxide were obtained with a two-step process utilizing plasma deposition and conventional chemical vapor deposition.

Chemical Vapor Deposition of Vanadium Oxide Tiiin Films

1993 ◽  
Vol 335 ◽  
Author(s):  
Ogie Stewart ◽  
Joan Rodriguez ◽  
Keith B. Williams ◽  
Gene P. Reck ◽  
Narayan Malani ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vanadium Oxide ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Pressure Chemical ◽  
Vanadium Oxide Thin Films ◽  
Deposited Films

AbstractVanadium oxide thin films were grown on glass substrates by atmospheric pressure chemical vapor deposition (APCVD) from the reaction of vanadium(IV) chloride with isopropanol and t-butanol. Films were deposited in the temperature range 250 to 450°C. The as-deposited films were a dark greenish color consistent with formation of a lower oxide of vanadium. Annealing a film deposited on Corning 7059 glass in air converted the material to a yellow film. X-ray diffraction of the yellow film revealed the presence of V2O5. Optical spectra of the films are presented. Glass substrates previously coated with conductive fluorine doped tin oxide were coated with V2O5 and evaluated for electrochromic activity.

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