A Study on unique Crystal Morphology observed in the Polycrystalline Copper CVD

2001 ◽  
Vol 672 ◽  
Author(s):  
Yuneng Chang ◽  
Yalian Chen ◽  
Kuanhon Chen
Keyword(s):  
Growth Rate ◽  
Water Vapor ◽  
Whisker Growth ◽  
Chemical Vapor ◽  
Axial Direction ◽  
Competitive Growth ◽  
Partial Pressures ◽  
Chromium Acetylacetonate ◽  
Pressure Chemical ◽  
Axial Growth

ABSTRACTNanostructure copper whisker growth was observed in an atmospheric pressure chemical vapor deposition (CVD) system, which used copper acetylacetonate vapor and 10-15 torr of water vapor as reactants, with 0.04-0.10 torr of chromium acetylacetonate vapor added as growth promoting catalyst. Water vapor initiated nucleation of these helical, spiral shape Cu(111) and (200) polycrystalline whiskers. While chromium acetylacetonate accelerated the growth rate. Copper whiskers had radii from 0.1 to 0.24 μm, lengths from 1 to 10 μm, and distribution density of 0.20-3.6 whiskers/μm2. Dependence of such whisker characteristics on temperature, partial pressures of H2O and chromium acetylacetonate was used to construct a kinetic model. From the Arrhenius equation, data analysis for whisker growth rate against deposition temperature showed that the activation energy for whisker growth along radial direction is 12.4 kcal/mol, and 19.6 kcal/mol for growth along axial direction. Based on such data and SEM observations, a base vapor-liquid-solid (VLS) model involving BCF theory was proposed to describe the governing mechanism for the axial growth. This model interpreted the competitive growth phenomena in both radial and axial directions, and controlling steps for radial and axial growth being assigned to mass transfer and surface reaction, respectively.

The Influence of Temperature Gradients on Partial Pressures in a Cvd Reactor

1993 ◽  
Vol 334 ◽  
Author(s):  
T.G.M. Oosterlaken ◽  
G.J. Leusink ◽  
G.C.A.M. Janssen ◽  
S. Radelaar ◽  
K.J. Kuijlaars ◽  
...  
Keyword(s):  
Soret Effect ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Temperature Gradients ◽  
Gaseous Species ◽  
Model Calculations ◽  
Influence Of Temperature ◽  
Effect Model ◽  
Partial Pressures ◽  
Pressure Chemical

AbstractThe influence of temperature gradients on the partial pressures of a binary mixture in a cold wall low pressure chemical vapor deposition reactor was determined by Raman spectroscopy of the gaseous species in the reactor. It is demonstrated for the first time that the partial pressure of the heavy constituent in the hot region of a low pressure reactor is reduced by 35 % due to the Soret effect. Model calculations that included the Soret effect are in agreement with the experimental data.

Development of Vertical 3×2〞LPCVD System for Fast Epitaxial Growth on 4H-SiC

2012 ◽  
Vol 717-720 ◽  
pp. 105-108 ◽  
Author(s):  
Wan Shun Zhao ◽  
Guo Sheng Sun ◽  
Hai Lei Wu ◽  
Guo Guo Yan ◽  
Liu Zheng ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Epitaxial Growth ◽  
Vapor Deposition ◽  
Growth Process ◽  
Chemical Vapor ◽  
Low Pressure ◽  
High Quality ◽  
Pressure Chemical ◽  
Homoepitaxial Layers

A vertical 3×2〞low pressure chemical vapor deposition (LPCVD) system has been developed to realize fast epitaxial growth of 4H-SiC. The epitaxial growth process was optimized and it was found that the growth rate increases with increasing C/Si ratio and tends to saturate when C/Si ratio exceeded 1. Mirror-like thick 4H-SiC homoepitaxial layers are obtained at 1500 °C and C/Si ratio of 0.5 with a growth rate of 25 μm/h. The minimum RMS roughness is 0.20 nm and the FWHM of rocking curves of epilayers grown for 1 hour and 2 hours are 26.2 arcsec and 32.4 arcsec, respectively. These results indicate that high-quality thick 4H-SiC epilayers can be grown successfully on the off-orientation 4H-SiC substrates.

Low pressure chemical vapor deposition of B-N-C-H films from triethylamine borane complex

1995 ◽  
Vol 10 (2) ◽  
pp. 320-327 ◽  
Author(s):  
R.A. Levy ◽  
E. Mastromatteo ◽  
J.M. Grow ◽  
V. Paturi ◽  
W.P. Kuo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Apparent Activation Energy ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Index Of Refraction ◽  
Arrhenius Behavior ◽  
Pressure Chemical

In this study, films consisting of B-N-C-H have been synthesized by low pressure chemical vapor deposition using the liquid precursor triethylamine borane complex (TEAB) both with and without ammonia. When no NH3 is present, the growth rate was observed to follow an Arrhenius behavior in the temperature range of 600 to 800 °C with an apparent activation energy of 11 kcal/mol. A linear dependence of growth rate is observed as a function of square root of flow rate for the TEAB range of 20 to 60 sccm, indicating that the reaction rate is controlled by the adsorption of borane. The addition of NH3 to TEAB had the effect of lowering the deposition temperature down to 300 °C and increasing the apparent activation energy to 22 kcal/mol. Above 650 °C, the carbon concentration of the deposits increased significantly, reflecting the breakup of the amine molecule. X-ray diffraction measurements indicated the films to be in all cases amorphous. Infrared spectra of the films showed absorption peaks representing the vibrational modes of B-N, B-N-B, B-H, and N-H. The index of refraction varied between 1.76 and 2.47, depending on composition of the films. Films deposited with no NH3 above 700 °C were seen to be compressive while films below that temperature were tensile. In the range of 350 to 475 °C, the addition of NH3 to TEAB resulted in films that were mildly tensile, while below 325 °C and above 550 °C, the films were found to be compressive. Both the hardness and Young's modulus of the films decreased with higher temperatures, reflecting the influence of the carbon presence.

A Study on Impact of Process Parameters to Metal Organic Chemical Vapor Deposition Grown (002) Zinc Oxide Thin Films, at 320°C

2002 ◽  
Vol 744 ◽  
Author(s):  
Yuneng Chang ◽  
Hengchuan Lu ◽  
Yumeng Hung ◽  
Chunsung Lee ◽  
Jianming Chen ◽  
...  
Keyword(s):  
Growth Rate ◽  
Water Vapor ◽  
Buffer Layer ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Zno Films ◽  
Key Factors ◽  
Si Substrates ◽  
Metal Organic ◽  
Zno Buffer Layer

ABSTRACTThis paper reports preparation of highly oriented (002) ZnO films by atmospheric pressure CVD at 320°C, which is far below previous reported values. In this study, a cold wall horizontal system was used to thermally decompose sublimed zinc acetylacetonate (Zn(acac)2, Zn(C5H702)2) vapor, and reacted with water vapor to produce ZnO films at temperatures above 320°C. Through experimental data, we discovered that low deposition temperature, using water vapor as co-reactant and substrates with ZnO buffer layer pre-coated by PVD are the key factors to prepare (002) ZnO films. By using Si(100) pre-coated with sputtered ZnO amorphous buffer layer as substrates, the ZnO growth rate is highest. While using copper oxide pre-coated Si substrates gave the lowest growth rate, and deposited ZnO film is amorphous. Considering influence of CVD co-reactant, using Zn(acac)2 and water vapor gives higher growth rate and better crystallinity than CVD using Zn(acac)2 and oxygen. Water vapor may supply hydrogen to react with released acetylacetonyl ligand (C5H7O2), and help the formation of stable acetylaceton (C5H8O2) molecule. DPA shows that film contain 46% O and 54% Zn. XPS of Zn Auger identified the valence of Zn being Zn2+. It seems that excessive Zn might present as discrete Zn2+ dispersed between ZnO lattices.

Tailored Deposition by LPCVD of Non-stoichiometric Si Oxides and their Application in the Formation of Si Nanocrystals Embedded in SiO2 by Thermal Annealing

2007 ◽  
Vol 989 ◽  
Author(s):  
Bruno Morana ◽  
Juan Carlos G. de Sande ◽  
Andrés Rodríguez ◽  
Jesús Sangrador ◽  
Tomás Rodríguez ◽  
...  
Keyword(s):  
Growth Rate ◽  
Vapor Deposition ◽  
Room Temperature ◽  
Silicon Oxide ◽  
Chemical Vapor ◽  
Design Experiment ◽  
Si Nanocrystals ◽  
Pressure Chemical ◽  
Face Centered ◽  
Central Composite

AbstractSilicon oxide films with excess of Si were deposited by Low Pressure Chemical Vapor Deposition. The growth rate of the films and the excess of silicon in them have been modeled using a Face-centered Central Composite Design experiment. Samples annealed at 1100°C show luminescence (665 nm) at 80K and at room temperature associated to Si nanocrystals.

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