Effect of Two-Step Deposition Process on Morphology and Optical Properties of Nanostructured Diamond Films

2013 ◽  
Vol 651 ◽  
pp. 148-153 ◽  
Author(s):  
S. Tipawan Khlayboonme ◽  
Wicharn Techitdheera ◽  
Warawoot Thowladda
Keyword(s):  
Optical Properties ◽  
Carbon Content ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Single Step ◽  
Second Step ◽  
Step Process

The morphology and optical properties of nanostructured diamond films affected by the two-step deposition process with changing CH4 concentration were investigated. The CH4 concentration was 1% for the first step and 2% for the second step. The films were prepared by chemical vapor deposition in a microwave plasma reactor with a CH4/H2 gas mixture. Nanocrystalline columnar-structured diamond film with lowering of sp2-bonded carbon content was achieved by the two-step deposition process. Unlike that of the single-step process with 1%CH4, the two-step process promoted the morphology to more uniform and smoother film. The two-step process increased the higher grain boundary as well as decreased the sp2-bonded carbon content in the film, as compared with the single-step process with 2%CH4Subscript text.

The Control Of Intrinsic Stresses In Cvd Diamond Films With Multistep Processing

1995 ◽  
Vol 416 ◽  
Author(s):  
S. Nijhawan ◽  
S. M. Jankovsky ◽  
B. W. Sheldon
Keyword(s):  
Thermal Stresses ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Annealing Treatment ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Internal Stresses ◽  
Tensile Stresses ◽  
Si Substrates

ABSTRACTThe role of intrinsic stresses in diamond films is examined. The films were deposited on (100) Si substrates by microwave plasma-enhanced chemical vapor deposition. The total internal stresses (thermal and intrinsic) were measured at room temperature with the bending plate method. The thermal stresses are compressive and arise due to the mismatch in thermal expansion coefficient of film and substrate. The intinsic stresses were tensile and evolved during the deposition process. These stresses increased with increasing deposition time. A 12 hour intermediate annealing treatment was found to reduce the tensile stresses considerably. The annealing treatment is most effective when the diamond crystallites are undergoing impingement and coalescence. This is consistent with the theory that the maximum tensile stresses are associated with grain boundary energetics.

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.

Infrared optical properties of CVD diamond films

1990 ◽  
Vol 5 (11) ◽  
pp. 2345-2350 ◽  
Author(s):  
X. H. Wang ◽  
L. Pilione ◽  
W. Zhu ◽  
W. Yarbrough ◽  
W. Drawl ◽  
...  
Keyword(s):  
Optical Properties ◽  
Microwave Plasma ◽  
Crystalline Silicon ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Optical Absorption Coefficient ◽  
Wave Number ◽  
Silicon Substrates ◽  
Free Standing ◽  
Infrared Optical Properties

Diamond films of 15–20 μm thicknesses were prepared by microwave plasma enhanced chemical vapor deposition onto crystalline silicon substrates. The growth surfaces of the films were rough with polycrystalline crystallographic habits, while the substrate sides of these films were smooth and featureless as viewed by optical microscopy. A heated cast iron scaife was used to polish the rough growth surfaces, and free-standing films were removed from the silicon substrates by dissolving the silicon in an aqueous HF. Both infrared optical transmission and reflection spectra were measured over the range of 600–4000 cm−1. For polished films, near 70% transmittance was obtained over the whole range, while the transmittance for nonpolished films was much lower and varied strongly with the wave number. Absorptions due to carbon-hydrogen stretching bands as well as a silicon carbide phase were observed in the transmission spectra. The optical absorption coefficient and the refractive index were found to vary from as high as 150 to as low as 7 cm−1 and 2.41 to 2.49, respectively (depending on the film quality and the wave number). A weak signature of the two-phonon absorption band of diamond was observed. The relationship between deposition conditions and infrared optical properties of diamond films before as well as after polishing is discussed.

The Contribution of H Ion Etching Under Different Substrate Bias to the Orientation Degree of Diamond Films

1998 ◽  
Vol 513 ◽  
Author(s):  
W. J. Zhang ◽  
X. Jiang
Keyword(s):  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Etching Process ◽  
Etching Time ◽  
Initial Growth ◽  
Substrate Bias ◽  
Ion Etching ◽  
Orientation Degree

ABSTRACTAn etching process of hydrogen ions was performed during the initial growth stage of diamond films. The H+ ion etching was performed by applying a negative substrate bias during a microwave plasma chemical vapor deposition process, using only hydrogen as a reactant gas. The contribution of H+ etching under different substrate bias and for different etching time to the orientation degree of diamond films was investigated by scanning electron microscopy and atomic force microscopy. It was found that an additional H+ etching process had influence on the orientation degree of deposited (001)-oriented diamond films. To achieve a significant improvement of crystal orientation, the bias voltage and etching time should be adjusted concerning to the situation of diamond films.

Growth-rate dependence of the thermal conductivity of chemical-vapor-deposited diamond

1999 ◽  
Vol 14 (9) ◽  
pp. 3720-3724 ◽  
Author(s):  
Naira M. Balzaretti ◽  
Albert Feldman ◽  
Edgar S. Etz ◽  
Roy Gat
Keyword(s):  
Thermal Conductivity ◽  
Growth Rate ◽  
Thermal Diffusivity ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Diffusivity Measurements ◽  
Chemical Vapor Deposited

The in-plane thermal diffusivity of chemical-vapor-deposited diamond films was measured as a function of diamond-growth rate. The films, 0.1–0.4 mm thick, were prepared in microwave-plasma reactor at growth rates ranging from 1 to 10 μm/h. A modification of Ångstöm's method was used to perform the diffusivity measurements. The thermal conductivity calculated from the thermal diffusivity shows an inverse relationship with growth rate. Analyses of Raman spectra indicate that both the line shifts and the line widths of the diamond Raman peak are practically independent of the deposition rate, except for the specimen grown at the highest growth rate.

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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