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).

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.

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.

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.

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.

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.

Characterization of High Quality, Large-Scale Growth of Monolayer WS2 Domains via Chemical Vapor Deposition Technique

2021 ◽  
Author(s):  
Somayeh Asgary ◽  
Amir Hoshang Ramezani ◽  
Zhaleh Ebrahimi Nejad
Keyword(s):  
Large Scale ◽  
Average Length ◽  
Chemical Vapor ◽  
Growth Time ◽  
High Quality ◽  
Force Microscopy ◽  
Atomic Force ◽  
Regular Triangle ◽  
Vapor Deposition Technique

Abstract WS2 flakes have been grown successfully on SiO2 substrate via chemical vapor (CVD) deposition method by reduction and sulfurization of WO3 using Ar/ H2 gas and sulfur evaporated from solid sulfur powder. The prepared samples were characterized by optical microscopy (OM), atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectra and photoluminescence (PL). Large domain WS2 monolayers are obtained by extending the growth time. The perfect triangular single-crystalline WS2 flakes with an average length of more than 35 µm were achieved. The sharp PL peak (∼1.98 eV) and two distinct Raman peaks (E2g and A1g) with a ∼ 71.5 cm-1 peak split indicating that relatively high quality WS2 crystals with a regular triangle shape can be synthesized. Higher growth time shows larger triangular-shaped of WS2.

scholarly journals Damage-free highly efficient plasma-assisted polishing of a 20-mm square large mosaic single crystal diamond substrate

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nian Liu ◽  
Kohki Sugawara ◽  
Naoya Yoshitaka ◽  
Hideaki Yamada ◽  
Daisuke Takeuchi ◽  
...  
Keyword(s):  
Single Crystal ◽  
Microwave Plasma ◽  
Removal Rate ◽  
Chemical Vapor ◽  
Plasma Chemical Vapor Deposition ◽  
Highly Efficient ◽  
Atomic Force ◽  
Diamond Substrate ◽  
Single Crystal Diamond ◽  
Measurement Results

Abstract Plasma-assisted polishing (PAP) as a damage-free and highly efficient polishing technique has been widely applied to difficult-to-machine wide-gap semiconductor materials such as 4H-SiC (0001) and GaN (0001). In this study, a 20-mm square large mosaic single crystal diamond (SCD) substrate synthesized by microwave plasma chemical vapor deposition (CVD) was polished by PAP. Argon-based plasma containing oxygen was used in PAP to modify the surface of quartz glass polishing plate, and a high material removal rate (MRR) of 13.3 μm/h was obtained. The flatness of SCD polished by PAP measured by an interferometer was 0.5 μm. The surface roughness measured by both scanning white light interferometer (SWLI) (84-μm square) and atomic force microscope (AFM) (5-μm square) was less than 0.5 nm Sq. The micro-Raman spectroscopy measurement results of mosaic SCD substrate processed by PAP showed that residual stress and non-diamond components on the surface after PAP processing were below the detection limit.

Thermal Stability of Nanocrystalline Diamond Films Grown by Microwave Plasma Chemical Vapor Deposition

2002 ◽  
Vol 750 ◽  
Author(s):  
Mevlut Bulut ◽  
Shane A. Catledge ◽  
Yogesh K. Vohra ◽  
Renato P. Camata
Keyword(s):  
Thermal Stability ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
Nanocrystalline Diamond Films ◽  
Thermal Stability Of

ABSTRACTIn this work, the open-air thermal stability of nanocrystalline diamond films grown on mirror-polished titanium alloy substrates by the Microwave Plasma Chemical Vapor Deposition (MPCVD) technique was studied. The results of this investigation show that nanocrystalline diamond films are highly stable in air up to 600°C with no significant change in mechanical properties. Samples annealed between 600°C and 650°C, however, exhibit values of hardness lower by as much as 40% compared to as-grown samples. Above 650°C serious delamination effects were observed in the coatings.

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