Synthesis of Diamond by Laser-Induced CVD

1986 ◽  
Vol 75 ◽  
Author(s):  
K. Kitahama ◽  
K. Hirata ◽  
H. Nakamatsu ◽  
S. Kawai ◽  
N. Fujimori ◽  
...  
Keyword(s):  
Gas Phase ◽  
Electronic Excitation ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Laser Power Density ◽  
Adsorbate Layer ◽  
Irradiation Geometry ◽  
Arf Excimer Laser ◽  
Reflection Electron Diffraction ◽  
Beam Deposition

AbstractSynthesis of diamond thin-films has been tried by an ArF excimer laser-induced chemical vapor deposition (LCVD) technique, using acetylene diluted with hydrogen as a source gas and a silicon wafer as a substrate. In these experiments, irradiation geometry, substrate temperature and laser power density were varied. Upon irradiation by a focused laser beam, deposition of diamond on substrates heated above 400°Cwas observed, and was confirmed by reflection electron diffraction (RED) photographs. Homogeneity of the diamond films was improved by irradiation parallel to the substrate. These facts suggest that the formation of diamond proceeds through multiple photon decomposition of the reactant gas, and that electronic excitation of gas phase rather than that of substrate or adsorbate layer is essential to form diamond.

Phase Transformation of Nanocrystalline Diamond Films: Effect of Methane Concentration

2020 ◽  
Vol 831 ◽  
pp. 127-131
Author(s):  
S.Tipawan Khlayboonme ◽  
Thowladda Warawoot
Keyword(s):  
Phase Transformation ◽  
Gas Phase ◽  
Electron Density ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Graphite Phase ◽  
Diamond Phase ◽  
Nanocrystalline Diamond Films

Ultra-nanocrystalline diamond films were prepared by a microwave plasma-enhanced chemical vapor deposition reactor using CH4/H2 gas mixture with a power as low as 650 W. The effects of CH4 concentration on nanostructure of the films and gas-phase species in plasma were investigated. The CH4 concentrations of 1.5%, 3.0%, 3.5%, and 4.0% were used and balanced with H2 to a total flow rate of 200 sccm. Morphology and composition of the films were characterized by SEM, Raman spectroscopy and Auger spectroscopy. The gas-phase species and electron density in the plasma were explored by optical emission spectroscopy and plasma-impedance measurement. The increasing CH4 concentration from 1.5% to 4.0% increased C2Hx species and decreased electron density. Phase of the film transform from nano- into ultranano- diamond phase but the growth rate revealingly decreased from 300 to 210 nm/h. Raman spectra indicate the higher CH4 concentration promted phase of the film transiton from NCD to UNCD. While Auger spectra revealed that UNCD film deposited with 4.0%CH4 was composed of 90.52% diamond phase but only 9.48% of graphite phase. The relation between phase transformation of the films and growth mechnism controlled by gas-phase species in the plasma will be dissused.

Modeling of Silicon Deposition Yield at Low Temperature by ArF Excimer Laser Photolysis of Disilane

1992 ◽  
Vol 263 ◽  
Author(s):  
B. Fowler ◽  
S. Lian ◽  
S. Krishnan ◽  
C. Li ◽  
L. Jung ◽  
...  
Keyword(s):  
Gas Phase ◽  
Excimer Laser ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Growth Surface ◽  
Phase Reaction ◽  
Gas Phase Reactions ◽  
Arf Excimer Laser ◽  
193 Nm

ABSTRACTNon-thermal Chemical Vapor Deposition (CVD) such as laser-enhanced photo-CVD of Si at low temperatures is important for Si-based heterostructures and doping superlattices. Growth kinetic models must be developed to allow these processes to be fully exploited. Intrinsic Si epitaxial layers were deposited at low substrate temperatures of 250-350ºC using the 193 nm output of an ArF excimer laser to directly dissociate Si2H6. The intrinsic film deposition rate can be described by a kinetic model that considers the gas phase reactions of the primary photolysis products and diffusion ofsilicon-bearing molecules to the growth surface. With the laser beam tangential to the substrate surface, growth rates as a function of beam-to-substrate distance have been characterized and indicate that very little gas phase reaction occurs for the dominant Si growth precursor. In order for intrinsic film deposition to result solely from Si2H6 photolysis products, a sticking coefficient ≥ 0.6 must be assigned to the dominant growth precursor in order to fit the observed yield of Si deposited in the films, indicating that the dominant growth precursor in 193 nm Si2H6 photolysis is perhaps H2SiSiH2.

Influence of the Gas Phase Composition on Nanocrystalline Diamond Films Prepared by MWCVD

2005 ◽  
Vol 23 ◽  
pp. 31-34 ◽  
Author(s):  
Cyril Popov ◽  
Miroslav Jelínek ◽  
S. Boycheva ◽  
V. Vorlícek ◽  
Wilhelm Kulisch
Keyword(s):  
Phase Composition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
Bonding Structure

Nanocrystalline diamond (NCD) films have been prepared by microwave plasma chemical vapor deposition (MWCVD) from methane/nitrogen mixtures, and the influence of the gas phase composition on the basic properties of the films (composition, morphology, topography, crystallinity and bonding structure) was investigated.

High-temperature electrical behavior of nanocrystalline and microcrystalline diamond films

2008 ◽  
Vol 23 (10) ◽  
pp. 2774-2786 ◽  
Author(s):  
N. Govindaraju ◽  
D. Das ◽  
R.N. Singh ◽  
P.B. Kosel
Keyword(s):  
High Temperature ◽  
Gas Phase ◽  
Room Temperature ◽  
Microelectromechanical Systems ◽  
Nitrogen Concentration ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Electrical Behavior ◽  
Nitrogen Concentrations ◽  
New Applications

Chemical vapor deposition of diamond has opened up new applications in microelectronics, microelectromechanical systems (MEMS), and coating technologies. This paper compares and contrasts the high-temperature electrical behavior of microcrystalline versus nanocrystalline diamond films. Through-thickness current–voltage characteristics between room temperature and 823 K are presented for a series of films synthesized with different gas phase concentrations of nitrogen and argon. One set of samples was characterized by measurements between room temperature and 823 K and a second set by two-step thermal cycling from room temperature to 573 and 823 K. It was found that with increasing nitrogen concentration (up to 0.1% N2), the resistivity slightly increased followed by a decrease at higher concentrations. Activation energies and barrier heights were in general lower for the more defective films. These results in conjunction with material characterization indicated that more defective diamond films were synthesized at higher nitrogen concentrations in the gas phase.

scholarly journals Thermochemical grinding of diamond films in installation for chemical vapor deposition of diamond from the gas phase

2020 ◽  
Vol 848 ◽  
pp. 012016
Author(s):  
S A Eremin ◽  
A M Kolesnikova ◽  
I A Leontiev ◽  
V N Anikin ◽  
O Yu Kudryashov ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor

A Novel TEM Technique for Characterizing As-Grown CVD Diamond Films

1991 ◽  
Vol 49 ◽  
pp. 956-957 ◽  
Author(s):  
Z.L. Wang ◽  
J. Bentley ◽  
R.E. Clausing ◽  
L. Heatherly ◽  
L.L. Horton
Keyword(s):  
Diamond Films ◽  
Chemical Vapor ◽  
Growth Direction ◽  
Dark Field ◽  
Growth Surface ◽  
Specimen Preparation ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
First Time ◽  
Microstructural Studies

Microstructural studies by transmission electron microscopy (TEM) of diamond films grown by chemical vapor deposition (CVD) usually involve tedious specimen preparation. This process has been avoided with a technique that is described in this paper. For the first time, thick as-grown diamond films have been examined directly in a conventional TEM without thinning. With this technique, the important microstructures near the growth surface have been characterized. An as-grown diamond film was fractured on a plane containing the growth direction. It took about 5 min to prepare a sample. For TEM examination, the film was tilted about 30-45° (see Fig. 1). Microstructures of the diamond grains on the top edge of the growth face can be characterized directly by transmitted electron bright-field (BF) and dark-field (DF) images and diffraction patterns.

Characterization of homoepitaxial diamond films by Electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 880-881
Author(s):  
D.P. Malta ◽  
S.A. Willard ◽  
R.A. Rudder ◽  
G.C. Hudson ◽  
J.B. Posthill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Large Degree ◽  
Rf Plasma ◽  
Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

scholarly journals Evolution of High-Quality Homoepitaxial CVD Diamond Films Induced by Methane Concentration

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 888
Author(s):  
Pengfei Zhang ◽  
Weidong Chen ◽  
Longhui Zhang ◽  
Shi He ◽  
Hongxing Wang ◽  
...  
Keyword(s):  
Methane Concentration ◽  
Flat Surface ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Plasma Chemical ◽  
High Quality ◽  
Effect Analysis ◽  
Plasma Chemical Vapor Deposition ◽  
Atomically Flat

In this paper, we successfully synthesized homoepitaxial diamond with high quality and atomically flat surface by microwave plasma chemical vapor deposition. The sample presents a growth rate of 3 μm/h, the lowest RMS of 0.573 nm, and the narrowest XRD FWHM of 31.32 arcsec. An effect analysis was also applied to discuss the influence of methane concentration on the diamond substrates.

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