Effect of Oxygen on Diamond Deposition in CH4/O2/H2 Gas Mixtures

1993 ◽  
Vol 334 ◽  
Author(s):  
H. Matsuyama ◽  
N. Sato ◽  
H. Kawakami
Keyword(s):  
Film Growth ◽  
Microwave Plasma ◽  
Gas Mixtures ◽  
Carbon Films ◽  
Diamond Growth ◽  
Growth Region ◽  
Gas Concentration ◽  
Oxygen Gas ◽  
Effect Of Oxygen ◽  
Plasma Emission Spectroscopy

AbstractDiamond growth experiments were carried out by a microwave plasma assisted CVD technique in various gas mixtures of CH4(0–100%)/02/H2. The phase diagram obtained by this study shows that a diamond growth region exists. With addition of more than 5% O2 in reactant gases, diamond particles could be included in amorphous or graphitic carbon films even using CH4/O2 gas mixtures. Faceted diamond films were obtained if the oxygen gas concentration [O2] was approximately more than half the methane gas concentration [CH4] ([O2]>[CH4]/2). However, no films were grown when [O2] exceeded half of [CH4] plus 7% ([O2]>[CH4]/2+7%). These results corresponded to the observations by plasma emission spectroscopy. Though oxygen etches carbon films and decomposes methane by forming carbon monoxide, oxygen rarely reacts with hydrogen in a film growth region.

Oxygen Effect in Diamond Deposition at Low Temperatures

1989 ◽  
Vol 162 ◽  
Author(s):  
Y. Liou ◽  
A. Inspektor ◽  
R. Weimer ◽  
D. Knight ◽  
R. Messier
Keyword(s):  
Thin Films ◽  
Low Temperatures ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Gas Mixtures ◽  
Diamond Growth ◽  
Oxygen Effect ◽  
Gas Mixture ◽  
Diamond Thin Films ◽  
Deposited Films

ABSTRACTDiamond thin films were deposited on different substrates at low temperatures (lowest temperature∼ 300°C, estimated) in a microwave plasma enhanced chemical vapor deposition (MPCVD) system. The deposited films were amorphous carbon or diamond films depending on the different gas mixtures used. The growth rate of diamond thin films was decreased by adding oxygen to the gas mixture. The addition of oxygen to the gas mixtures was found to be important for diamond growth at low temperatures. Different concentrations of oxygen have been added into the gas mixture. Without oxygen, the deposited films were white soots and easily scratched off. Increasing the oxygen input improved the quality of the Raman peaks and increased the film transpancy. The diamond films were also characterized by scanning electron microscopy (SEM).

Residual Stresses Analysis in Diamond Layers Deposited on Various Substrates

1995 ◽  
Vol 383 ◽  
Author(s):  
D. Rats ◽  
L. Bimbault ◽  
L. Vandenbulcke ◽  
R. Herbin ◽  
K. F. Badawi
Keyword(s):  
Residual Stresses ◽  
Thermal Stresses ◽  
Film Growth ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Gas ◽  
Deposition Conditions

ABSTRACTA major problem for diamond coating applications is that diamond films tend to exhibit poor adherence on many. substrates and typically disbond at thicknesses of the order of few micrometers due especially to residual stresses. Residual stresses in diamond are composed of thermal expansion mismatch stresses and intrinsic stresses induced during film growth. Diamond films were deposited in a classical microwave plasma reactor from hydrocarbon-hydrogen-oxygen gas mixtures. Thermal stresses were directly calculated from Hook's law. On silicon substrate, intrinsic stresses were deduced by difference from measurements of total stresses either by the curvature method or by X-ray diffraction using the sin 2ψ method. These investigations allow us to discuss the origin of the intrinsic stresses. The residual stress level was also investigated by Raman spectroscopy as a function of the deposition conditions and substrate materials (SiO2, Si3N4, Si, SiC, WC-Co, Mo and Ti-6A1-4V). We show that the thermal stresses are often preponderant.

FIELD EMISSION STUDIES OF NITROGEN-DOPED DIAMOND-LIKE CARBON FILMS DEPOSITED USING CH4/N2/Ne and CH4/NH3/Ne RF PLASMAS

2000 ◽  
Vol 14 (02n03) ◽  
pp. 295-300 ◽  
Author(s):  
M. T. KUO ◽  
P. W. MAY ◽  
A. GUNN ◽  
J. C. MARSHALL ◽  
M. N. R. ASHFOLD ◽  
...  
Keyword(s):  
Growth Rate ◽  
Field Emission ◽  
Flow Rate ◽  
Threshold Voltage ◽  
Film Growth ◽  
Maximum Growth ◽  
Gas Mixtures ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
N Content

Hydrogenated diamond-like Carbon (DLC) films have been deposited on Si substrates using CH 4-based radio-frequency plasmas. The films have been doped with nitrogen by addition of either N2 or NH 3 into the source gas mixture, producing films with up to 16% and 25% N content, respectively. The effect of additions of Ne to these gas mixtures has been investigated as a possible method to increase the growth rate and the N-content of the films. We find that addition of Ne increases the film growth rate until the Ne flow rate equals that of the CH 4, giving maximum growth rate increases of 70% and 200% for NH 3 and N 2 containing gas mixtures, respectively. At the same time the field emission threshold voltage decreases by a factor of ~0.5 and 2, respectively. With further increases in Ne flow rate, the film growth rates decrease in both cases, whilst the threshold voltage increases. Micro-combustion measurements show that the N content within the films is proportional to the percentage of the N-containing precursor in the gas phase, but is independent of Ne concentration.

scholarly journals Comparison of diamond growth with different gas mixtures in microwave plasma asssited chemical vapor deposition (MWCVD)

2003 ◽  
Vol 6 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Evaldo J. Corat ◽  
Neidenei G. Ferreira ◽  
Nélia F. Leite ◽  
Vladimir J. Trava-Airoldi
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Gas Mixtures ◽  
Diamond Growth

Simulations of CVD Diamond Film Growth: 2D Models for the identities and concentrations of gas-phase species adsorbing on the surface

2011 ◽  
Vol 1282 ◽  
Author(s):  
Paul W. May ◽  
Yuri A. Mankelevich
Keyword(s):  
Gas Phase ◽  
Film Growth ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
Diamond Surface ◽  
Diamond Growth ◽  
Process Conditions ◽  
Ultrananocrystalline Diamond ◽  
Single Crystal Diamond

ABSTRACTA prerequisite for modelling the growth of diamond by CVD is knowledge of the identities and concentrations of the gas-phase species which impact upon the growing diamond surface. Two methods have been devised for the estimation of this information, and have been used to determine adsorption rates for CxHy hydrocarbons for process conditions that experimentally produce single-crystal diamond, microcrystalline diamond films, nanocrystalline diamond films and ultrananocrystalline diamond films. Both methods rely on adapting a previously developed model for the gas-phase chemistry occurring in a hot filament or microwave plasma reactor. Using these methods, the concentrations of most of the CxHy radical species, with the exception of CH3, at the surface have been found to be several orders of magnitude smaller than previously believed. In most cases these low concentrations suggest that reactions such as direct insertion of C1Hy (y = 0-2) and/or C2 into surface C–H or C–C bonds can be neglected and that such species do not contribute significantly to the diamond growth process in the reactors under study.

Effect of Oxygen on the Textured Diamond Growth over Nickel Substrates

1994 ◽  
Vol 339 ◽  
Author(s):  
R. Ramesham ◽  
M. F. Rose ◽  
R. F. Askew ◽  
M. Bozack
Keyword(s):  
Etch Rate ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Diamond Growth ◽  
Entire Surface ◽  
Raman Analysis ◽  
Nickel Substrates ◽  
Effect Of Oxygen ◽  
Deposited Films

ABSTRACTMicrowave plasma has been used to grow diamond films using CH4 and H2 over nickel substrates. Nucleation of the diamond has been achieved by manual scratching and ultrasonic agitation of the substrates. The substrate was left in the H 2 microwave plasma to remove any oxide film present prior to the diamond growth. According to SEM the morphology of the grown films was (100) textured over the entire surface. Our interest is to study the effect of O2 on the growth rate and the morphology of as-deposited diamond films. Infact, O2 has a tendency to preferentially etch the diamond (etch rate: 111 > 110 >100). Injection of O2 into the reaction mixture could enhance the 100 texture further. Raman analysis confirms the deposited films as diamond. Effect of O2 on the nature of the films and the characterization of as-deposited films is described.

scholarly journals Deposition of Boron-Doped Thin CVD Diamond Films from Methane-Triethyl Borate-Hydrogen Gas Mixture

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 666 ◽  
Author(s):  
Nikolay Ivanovich Polushin ◽  
Alexander Ivanovich Laptev ◽  
Boris Vladimirovich Spitsyn ◽  
Alexander Evgenievich Alexenko ◽  
Alexander Mihailovich Polyansky ◽  
...  
Keyword(s):  
Film Growth ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Diamond Growth ◽  
Structural Defects ◽  
Boron Doped Diamond ◽  
Diamond Deposition ◽  
Synthesis Conditions ◽  
Surface Etching ◽  
Boron Doped

Boron-doped diamond is a promising semiconductor material that can be used as a sensor and in power electronics. Currently, researchers have obtained thin boron-doped diamond layers due to low film growth rates (2–10 μm/h), with polycrystalline diamond growth on the front and edge planes of thicker crystals, inhomogeneous properties in the growing crystal’s volume, and the presence of different structural defects. One way to reduce structural imperfection is the specification of optimal synthesis conditions, as well as surface etching, to remove diamond polycrystals. Etching can be carried out using various gas compositions, but this operation is conducted with the interruption of the diamond deposition process; therefore, inhomogeneity in the diamond structure appears. The solution to this problem is etching in the process of diamond deposition. To realize this in the present work, we used triethyl borate as a boron-containing substance in the process of boron-doped diamond chemical vapor deposition. Due to the oxygen atoms in the triethyl borate molecule, it became possible to carry out an experiment on simultaneous boron-doped diamond deposition and growing surface etching without the requirement of process interruption for other operations. As a result of the experiments, we obtain highly boron-doped monocrystalline diamond layers with a thickness of about 8 μm and a boron content of 2.9%. Defects in the form of diamond polycrystals were not detected on the surface and around the periphery of the plate.

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