Coherent island formation of Cu2O films grown by chemical vapor deposition on MgO(110)

2001 ◽  
Vol 16 (8) ◽  
pp. 2408-2414 ◽  
Author(s):  
P. R. Markworth ◽  
X. Liu ◽  
J. Y. Dai ◽  
W. Fan ◽  
T. J. Marks ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Strain Relaxation ◽  
Three Dimensional ◽  
High Mobility ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Growth Conditions ◽  
Island Formation ◽  
Transmission Electron

Cuprous oxide (Cu2O) films have been grown on single-crystal MgO(110) substrates by a chemical vapor deposition process in the temperature range 690–790 °C. X-ray diffraction measurements show that phase-pure, highly oriented Cu2O films form at these temperatures. The Cu2O films are observed to grow by an island-formation mechanism on this substrate. Films grown at 690 °C uniformly coat the substrate except for micropores between grains. However, at a growth temperature of 790 °C, an isolated, three-dimensional island morphology develops. Using a transmission electron microscopy and atomic force microscope, both dome- and hut-shaped islands are observed and are shown to be coherent and epitaxial. The isolated, coherent islands form under high mobility growth conditions where geometric strain relaxation occurs before misfit dislocation can be introduced. This rare observation for oxides is attributed to the relatively weak bonding of Cu2O, which also has a relatively low melting temperature.

Electron Beam Assisted Chemical Vapor Deposition of Gold in an Environmental Tem

1995 ◽  
Vol 388 ◽  
Author(s):  
John Kouvetakis ◽  
Renu SharmA ◽  
B. L. Ramakrisna ◽  
Jeff Drucker ◽  
Paul Seidler
Keyword(s):  
Electron Beam ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Deposition Process ◽  
In Situ Observation ◽  
Beam Irradiation ◽  
Environmental Tem ◽  
Diffraction Patterns

AbstractWe demonstrate a novel technique for in situ observation of the chemical vapor deposition of high purity gold using ethyl(trimethylphosphine)gold(I). an environmental transmission electron microscope with 3.8 eV resolution was used to observe and compare the growth of the material with or without electron beam irradiation (120 keV) with Si (100) substrate temperatures ranging from 125-200 °C. Typical precursor pressures of 10-4 Torr and E-beam irradiation resulted in rapid growth of virtually continuous gold films. thermal deposition without the beam resulted in low nucleation densities, low deposition rates, and island-like growth. Images and diffraction patterns acquired during the deposition process indicated polycrystalline gold and elemental analysis at the nanometer scale showed that the films had excellent chemical purity. atomic force microscopy was also used to investigate the three dimensional morphology of the materials. the most notable result of the deposition process is the dramatic enhancement of the growth rate due to the beam irradiation.

The Use of Novel Organometallic Sources in Metal Organic Chemical Vapor Deposition (MOCVD)

1992 ◽  
Vol 282 ◽  
Author(s):  
R. M. Biefeld
Keyword(s):  
Chemical Vapor Deposition ◽  
Surface Morphology ◽  
Vapor Deposition ◽  
High Mobility ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Similar Growth

ABSTRACTIn metal organic chemical vapor deposition (MOCVD), the most commonly used sources are the trimethyls of Al, Ga, In, and Sb, and PH3 and ASH3. New organometallic sources are being developed as the understanding of the deposition process improvesand allows for the determination of the effects of source type and growth condition on the properties of the grown films. These new sources are safer and allow for the growth of higher purity materials using more favorable growth conditions. InSb and AlSb prepared using these trimethyl-sources are not of high enough quality to be used in many current device applications. Alternate organometallic Sb sources are being investigated to improve the materials characteristics of InSb grown by MOCVD.InSb grown using trimethylindium (TMIn) and trimethylantimony (TMSb) or triethylantimony (TESb) yielded similar quality materials under similar growth conditions. InSb grown using triethylindium (TEIn) and TESb under similar growth conditions yielded very poor quality n-type material. Three new organometallic Sb sources, triisopropylantimony (TIPSb), tris(dimethylamino)antimony (TDMASb), and tertiarybutyldimethylantimony (TBDMSb) are being investigated. The growth of InSb using TIPSb, TDMASb, or TBDMSb and TMIn was investigated over a temperature range of 350 to 475 °C. InSb grown from TDMASb had similar properties to InSb grown from TMIn and TMSbwhen using a similar temperature and V/III ratio range. The growth rates of InSb using TMIn and either TIPSb or TBDMSb at temperatures <= 425 °C were proportional to both the TMIn flow rate and the temperature. The surface morphology of InSb grown using eitherTIPSb or TBDMSb was very rough for growth temperatures <=425 °C. This may be due to the complex decomposition mechanisms involved and the presence of methyl groups on the surface. The InSb with the highest mobility was grown at 400 °C and a V/III ratioof 3 using TIPSb. It was n-type with a carrier concentration of 2.5 × 1015 cm−3 and a mobility of 78,160 cm2/Vs at 77 K. Both n- and p-type InSb were grown using TBDMSb with mobilities up to 67,530 and 7773 cm2/Vs, respectively at 77 K. The mobility for InSb using either TIPSb or TBDMSb was optimized by going to lower temperatures, pressures and V/III ratios. The opposite was truefor surface morphology which improved with higher temperature, pressure, and V/III ratio. The growth of high mobility InSb with smooth surfaces at T<=425 °C was not achieved with TIPSb or TBDMSb and TMIn under the conditions investigated in this work.

A Three-Dimensional Analysis of the Flow and Heat Transfer for the Modified Chemical Vapor Deposition Process Including Buoyancy, Variable Properties, and Tube Rotation

1991 ◽  
Vol 113 (2) ◽  
pp. 400-406 ◽  
Author(s):  
Y. T. Lin ◽  
M. Choi ◽  
R. Greif
Keyword(s):  
Heat Transfer ◽  
Chemical Vapor Deposition ◽  
Secondary Flow ◽  
Vapor Deposition ◽  
Axial Velocity ◽  
Particle Deposition ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Variable Properties

A study has been made of the heat transfer, flow, and particle deposition relative to the modified chemical vapor deposition (MCVD) process. The effects of variable properties, buoyancy, and tube rotation have been included in the study. The resulting three-dimensional temperature and velocity fields have been obtained for a range of conditions. The effects of buoyancy result in asymmetric temperature and axial velocity profiles with respect to the tube axis. Variable properties cause significant variations in the axial velocity along the tube and in the secondary flow in the region near the torch. Particle trajectories are shown to be strongly dependent on the tube rotation and are helices for large rotational speeds. The component of secondary flow in the radial direction is compared to the thermophoretic velocity, which is the primary cause of particle deposition in the MCVD process. Over the central portion of the tube the radial component of the secondary flow is most important in determining the motion of the particles.

Chemical vapor deposition of α – ZrP whiskers

1996 ◽  
Vol 11 (5) ◽  
pp. 1157-1163 ◽  
Author(s):  
S. Motojima ◽  
S. Hirano ◽  
K. Kurosawa ◽  
H. Iwanaga
Keyword(s):  
Chemical Vapor Deposition ◽  
Cross Sections ◽  
Vapor Deposition ◽  
Whisker Growth ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Growth Conditions ◽  
Growth Direction ◽  
Metal Impurity ◽  
Ar Gas

α–ZrP whiskers have been prepared from ZrCl4 + PCl3 + H2 + Ar gas mixtures at 1050–1250 °C using the mixed metal impurity-activated chemical vapor deposition process. The growth conditions, morphology, growth mechanism, and some properties were examined. The mixed impurities of Si + Pt and Si + Pd were very effective for the ZrP whisker growth with 8–12 mm (avg. 10 mm) long whiskers being obtained at 1300 °C for 1 h. The growth direction of the whiskers having hexagonal and square cross sections were along the c-axis and a-axis, respectively. The whiskers were very stable to an 80 min immersion in a concentrated HCl solution.

Generation of carbon tripods on copper by chemical vapor deposition

1999 ◽  
Vol 14 (2) ◽  
pp. 560-564 ◽  
Author(s):  
F. Le Normand ◽  
L. Constant ◽  
G. Ehret ◽  
C. Speisser
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Growth Conditions ◽  
Chemical Vapor Deposition Process ◽  
Diamond Growth ◽  
Limited Size ◽  
Forms Of Carbon ◽  
Vapor Deposition Process

We report the first observation of large graphitic capped clusters with threefold symmetry (tripods). They were generated under the diamond growth conditions by the chemical vapor deposition process activated by hot filaments on a Cu(111) surface while conditions of very poor diamond nucleation (104–105 cm-2) are fullfilled. They were characterized by direct high resolution imaging and selected area diffraction. Furthermore, a lot of them are connected. The behavior of hydrogen radicals to curl and to close limited-size graphitic planes is emphasized to explain their formation. These tripods appear to be readily stable carbon as they form only after other limited-size graphitic clusters such as graphite lumps or bucky onions. It is thus expected that the chemical vapor deposition process is a quite relevant preparation method to grow in a controlled way new forms of carbon with a narrow size distribution.

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