scholarly journals Synthesis of ultrasmooth nanostructured diamond films by microwave plasma chemical vapor deposition using a He/H2/CH4/N2gas mixture

2006 ◽  
Vol 21 (10) ◽  
pp. 2675-2682 ◽  
Author(s):  
S. Chowdhury ◽  
Damon A. Hillman ◽  
Shane A. Catledge ◽  
Valery V. Konovalov ◽  
Yogesh K. Vohra
Keyword(s):  
Gas Flow ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Optical Emission ◽  
X Ray Diffraction ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gas Flow Ratio

Ultrasmooth nanostructured diamond (USND) films were synthesized on Ti–6Al–4V medical grade substrates by adding helium in H2/CH4/N2plasma and changing the N2/CH4gas flow from 0 to 0.6. We were able to deposit diamond films as smooth as 6 nm (root-mean-square), as measured by an atomic force microscopy (AFM) scan area of 2 μm2. Grain size was 4–5 nm at 71% He in (H2+ He) and N2/CH4gas flow ratio of 0.4 without deteriorating the hardness (∼50–60 GPa). The characterization of the films was performed with AFM, scanning electron microscopy, x-ray diffraction (XRD), Raman spectroscopy, and nanoindentation techniques. XRD and Raman results showed the nanocrystalline nature of the diamond films. The plasma species during deposition were monitored by optical emission spectroscopy. With increasing N2/CH4feedgas ratio (CH4was fixed) in He/H2/CH4/N2plasma, a substantial increase of CN radical (normalized by Balmer Hαline) was observed along with a drop in surface roughness up to a critical N2/CH4ratio of 0.4. The CN radical concentration in the plasma was thus correlated to the formation of ultrasmooth nanostructured diamond films.

Study of the Adhesion and Biocompatibility of Nanocrystalline Diamond (NCD) Films on 3C-SiC Substrates

2009 ◽  
Vol 1203 ◽  
Author(s):  
Humberto Gomez ◽  
Christopher L. Frewin ◽  
Ashok Kumar ◽  
Stephen Saddow ◽  
Christopher Locke
Keyword(s):  
Microwave Plasma ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Grain Structure ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis ◽  
Fixed Cell

AbstractThe unique material characteristics of silicon carbide (SiC) and nanocrystalline diamond (NCD) present solutions to many problems in conventional MEMS applications and especially for biologically compatible devices. Both materials have a wide bandgap along with excellent optical, thermal and mechanical properties. Initial experiments were performed for NCD films grown on 3C-SiC using a microwave plasma chemical vapor deposition (MPCVD) reactor. It was observed from the atomic force microscopy (AFM) analysis that the NCD films on 3C-SiC possess a more uniform grain structure, with sizes ranging from approximately 5 – 10 nm, whereas on the Si surface, the NCD has large, non-unioform inclusions of grains ≈1 μm in size. The in vitro biocompatibility performance of NCD/3C-SiC was measured utilizing 2 immortalized neural cell lines: H4 human neuroglioma (ATCC #HTB-148) and PC12 rat pheochromocytoma (ATCC #CRL-1721). MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to measure viability of the cells for 96 hours and live/ fixed cell. AFM was performed to determine the general cell morphology. The H4 cell line shows a good biocompatibility level with hydrogen treated NCD as compared with the cell treated polystyrene control well, while the PC12 cells show decreased viability on the NCD surfaces.

Low Temperature Growth of CVD Nanocrystalline Diamond Thin Film by Designed SWP-CVD with Various Working Pressures

2019 ◽  
Vol 11 (9) ◽  
pp. 1292-1297
Author(s):  
Yeong Min Park ◽  
Moon Ki Han ◽  
Mun Ki Bae ◽  
Tae Gyu Kim
Keyword(s):  
Microwave Plasma ◽  
Chemical Properties ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Slot Antenna ◽  
High Quality ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Diamond Thin Film ◽  
Atomic Force

Nanocrystalline diamond (NCD) is exceptionally useful for a variety of applications and is of significant interest to researchers in technological and scientific fields due to its excellent mechanical and chemical properties, such as its hardness and high thermal conductivity. We have modified a microwave plasma chemical vapor deposition (MPCVD; Astex Inc.) system with a slot antenna designed for surface wave plasma (SWP) and successfully fabricated high quality thin NCD film. This SWP-CVD process fabricates high quality diamond film at 300 °C, while a normal MPCVD process requires the temperature of the substrate to be above 800 °C. We studied the fabricated NCD samples in detail, measuring their surface morphology by field emission scanning electron microscopy (FESEM); their structural-chemical properties by Raman spectroscopy; and their surface roughness by atomic force microscopy (AFM).

scholarly journals Simulation-Based Development of a New Cylindrical-Cavity Microwave-Plasma Reactor for Diamond-Film Synthesis

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 320 ◽  
Author(s):  
Qijun Wang ◽  
Gai Wu ◽  
Sheng Liu ◽  
Zhiyin Gan ◽  
Bo Yang ◽  
...  
Keyword(s):  
Cylindrical Cavity ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Optical Microscope ◽  
Plasma Chemical Vapor Deposition ◽  
Atomic Force ◽  
Single Crystal Diamond ◽  
Film Synthesis

A 2.45 GHz microwave-plasma chemical-vapor deposition (MPCVD) reactor was designed and built in-house by collaborating with Guangdong TrueOne Semiconductor Technology Co., Ltd. A cylindrical cavity was designed as the deposition chamber and a circumferential coaxial-mode transformer located at the top of the cavity was adopted as the antenna. Two quartz-ring windows that were placed far away from the plasma and cooled by water-cooling cavity walls were used to affix the antenna to the cavity and act as a vacuum seal for the reactor, respectively. This design improved the sealing and protected the quartz windows. In addition, a numerical simulation was proposed to predict the electric-field and plasma-density distributions in the cavity. Based on the simulation results, a microwave-plasma reactor with TM021 mode was built. The leak rate of this new reactor was tested to be as low as 1 × 10−8 Pa·m3·s−1, and the maximal microwave power was as high as 10 kW. Then, single-crystal diamond films were grown with the morphology and crystalline quality characterized by an optical microscope, atomic force microscope (AFM), Raman spectrometer, photoluminescence (PL) spectrometer, and high-resolution X-ray diffractometer. It was shown that the newly developed MPCVD reactor can produce diamond films with high quality and purity.

Growth of Diamond Films Using C3F8AND H2in A New System

1994 ◽  
Vol 349 ◽  
Author(s):  
Ping Huangfu ◽  
Zengsun Jin ◽  
Xianyi Lu ◽  
Guangtian Zou ◽  
Huaxian Xiao ◽  
...  
Keyword(s):  
Synthetic Diamond ◽  
Diamond Films ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Surface Pretreatment ◽  
Force Microscopy ◽  
Atomic Force ◽  
Single Crystal Diamond ◽  
New System

ABSTRACTIn the present study, the new system used C3F8and H2 as source gases. Filament-assisted chemical vapor deposition was utilized. Continuous diamond films were grown on the Si and Mo substrates without any surface pretreatment. The results of scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and atomic force microscopy measurements indicate that the films deposited on the Mo substrates are of high quality. Homoepitaxial diamond films were grown on the high pressure synthetic single crystal diamond substrates. The results show that in our experimental conditions epitaxial films were easily grown on the (111) synthetic diamond substrates and sometimes epitaxial filmse also grown on the (100) synthetic diamond substrates.

Multivariable study on homoepitaxial diamond growth using isotopically enriched carbon-13 gas mixtures

2009 ◽  
Vol 24 (2) ◽  
pp. 493-498 ◽  
Author(s):  
Gopi K. Samudrala ◽  
Yogesh K. Vohra
Keyword(s):  
Microwave Plasma ◽  
Chemical Vapor ◽  
Nitrogen Vacancy ◽  
Diamond Growth ◽  
Plasma Chemical ◽  
Rocking Curve ◽  
X Ray ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Atomic Force

We report our observations on the homoepitaxial diamond growth by microwave plasma chemical vapor deposition (MPCVD) experiments on Type Ib diamond substrates conducted by varying three independent variables. In a feed gas mixture of H2, N2, O2, and 13CH4, the amount of nitrogen was varied in the range of 0 to 4000 ppm, the amount of methane was varied from 2% CH4/H2 to 6% CH4/H2, and the substrate temperature was varied in the range of 850 to 1200 °C. We used isotopically enriched carbon-13 methane gas as the source of carbon in the plasma to clearly distinguish the grown diamond layer from the underlying substrate using Raman spectroscopy. The x-ray rocking curve measurements confirmed the homoepitaxial nature of the deposited layers with a slight increase in the full width at half-maximum for sample grown with the highest nitrogen content in the plasma. Optical and atomic force microscopy revealed dramatic changes in surface morphology with variation in each parameter. The nitrogen incorporation in carbon-13 diamond layers was monitored through photoluminescence spectroscopy of nitrogen–vacancy complexes. A twentyfold increase in diamond growth rate was clearly achieved in this multivariable study.

Low-temperature growth of HfO2 dielectric layers by Plasma-Enhanced CVD

2003 ◽  
Vol 786 ◽  
Author(s):  
M. Losurdo ◽  
M.M. Giangregorio ◽  
M. Luchena ◽  
P. Capezzuto ◽  
G. Bruno ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Growth Dynamics ◽  
Chemical Vapor ◽  
Optical Emission ◽  
Interface Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dielectric Layers

ABSTRACTHfO2 dielectric layers have been grown on p -type Si(100) by plasma enhanced chemical vapor deposition (PE-CVD), using Ar-O2 plasmas and hafnium(IV) tetra-t -butoxide as precursors. In-situ control of the plasma phase is carried out by optical emission spectroscopy (OES) and quadrupolar mass spectrometry (QMS).Structural and optical properties of the HfO2 layers and of the HfO2/Si interface are investigated by spectroscopic ellipsometry (SE) in the photon energy range 1.5–6.0 eV‥ SE data are corroborated by results obtained from glancing incidence X-ray diffraction (GIXRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS).The effect of the substrate temperature (RT-250°C) and precursor flow on the thickness of interfacial SiO2 layer and on the HfO2 microstructure is investigated. The growth dynamics of HfO2 film and SiO2 interface layer is also discussed.

Morphology of heavily B-doped diamond films

1993 ◽  
Vol 8 (11) ◽  
pp. 2845-2857 ◽  
Author(s):  
Koichi Miyata ◽  
Kazuo Kumagai ◽  
Kozo Nishimura ◽  
Koji Kobashi
Keyword(s):  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Plasma Chemical ◽  
X Ray ◽  
Plasma Chemical Vapor Deposition ◽  
Si Substrates ◽  
Surface Morphologies

B-doped diamond films were synthesized by microwave plasma chemical vapor deposition using a mixture of methane (0.5% or 1.2%) and diborane (B2H6) below 50 ppm on either Si substrates or undoped diamond films that had been synthesized using 0.5% or 1.2% methane. The surface morphologies of the synthesized films were observed by Secondary Electron Microscopy, and the infrared absorption and Raman spectra were measured. It was found that when diborane concentration was low, B-doped films preferred (111) facets. On the other hand, high diborane concentrations resulted in a deposition of needle-like material that was identified as graphite by x-ray diffraction.

Growth of highly (111)-oriented, highly coalesced diamond films on platinum (111) surface: A possibility of heteroepitaxy

1996 ◽  
Vol 11 (12) ◽  
pp. 2955-2956 ◽  
Author(s):  
Yoshihiro Shintani
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Plasma Chemical ◽  
X Ray ◽  
Plasma Chemical Vapor Deposition ◽  
Scanning Electron

A highly (111)-oriented, highly coalesced diamond film was grown on platinum (111) surface by microwave plasma chemical vapor deposition (MPCVD). Scanning electron microscopy and x-ray diffraction analyses revealed that the (111) diamond facets were azimuthally oriented epitaxially with respect to the orientation of the Pt(111) domain underneath, with the neighboring facets of diamond being coalesced with each other. The film was confirmed as diamond using Raman spectroscopy.

Nitrogen-Induced Nanocrystallinity of CVD Diamond Films on Ti-6Al-4V Alloys

1998 ◽  
Vol 555 ◽  
Author(s):  
Shane A. Catledge ◽  
Yogesh K. Vohra
Keyword(s):  
Microwave Plasma ◽  
Grazing Angle ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Structure ◽  
Optical Emission ◽  
High Density ◽  
Operating Pressure ◽  
Plasma Chemical Vapor Deposition ◽  
Density Plasma

AbstractMicrowave plasma chemical vapor deposition (CVD) was used to grow nanocrystalline diamond films by adding nitrogen to a high density plasma defined by a high operating pressure (125 Torr) and high methane feedgas concentration (15% in a balance of hydrogen). Films grown at these conditions but without nitrogen exhibited well-faceted, high phase purity crystalline diamond while those grown with added nitrogen showed a nanocrystalline structure and were an order of magnitude smoother. The nitrogen-induced nanocrystalline films are believed to be comprised predominantly of diamond nanocrystallites in a matrix of tetrahedral amorphous carbon. The films were characterized by Raman spectroscopy, grazing-angle x-ray diffraction, surface profilometry, nano-indentation, electron microscopy, and pin-on-disc tribometry. In contrast to standard CVD conditions, the high density plasma results in adhered films on Ti-6AI-4V substrates even at substrate temperatures of 850°C. We present plasma optical emission spectroscopy results which are correlated with changes in the Raman spectra and the film microstructure. The hardness of the films (∼90 GPa), their low rms surface roughness (27 nm), and their good adhesion to the substrate makes these films potentially useful for tribological applications.

EFFECT OF DEPOSITING TEMPERATURE ON THE INTERFACIAL ADHESION OF NANOCRYSTALLINE DIAMOND FILMS GROWN ON TITANIUM BY MICROWAVE PLASMA ASSISTED CVD PROCESS

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1725-1732
Author(s):  
SYED JAWID ASKARI ◽  
ALI IMRAN MERCHANT
Keyword(s):  
Microwave Plasma ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Complex Nature ◽  
Nucleation Density ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Thermal Expansion Coefficients ◽  
Atomic Force ◽  
Indentation Tests

In contrast to their exceptional mechanical properties, titanium and its alloys possess poor friction and wear characteristics. Nanocrystalline diamond (NCD) films appear to be a promising solution for their tribological problem due to their smooth surfaces and small grain size. However, the synthesis of a well adherent NCD film on titanium and its alloys is always complicated due to the different thermal expansion coefficients of the two materials, the complex nature of the interlayer formed during diamond deposition, and the difficulty in achieving very high nucleation density. In this work NCD thin films have been deposited on pure Ti substrates in a microwave plasma chemical vapor deposition (MWPCVD) reactor under fixed pressure and methane concentration in hydrogen but over a wide temperature range. The effects of depositing temperatures on the adhesion of films are evaluated using Rockwell indentation tests. It is found that by increasing the deposition temperature the films bonding deteriorates. The films synthesized are characterized by field emission scanning electron microscopy, atomic force microscopy, Raman spectroscopy, and X-ray diffraction.

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