Area Selective Laser Chemical Vapor Deposition of Diamond

1995 ◽  
Vol 397 ◽  
Author(s):  
M. Lindstam ◽  
M. Boman ◽  
K. Larsson ◽  
G. Stenberg ◽  
J.-O. Carlsson
Keyword(s):  
Substrate Temperature ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Scanning Force Microscopy ◽  
Silicon Substrates ◽  
Laser Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Scanning Force ◽  
Hot Filament

ABSTRACTHigh quality diamond spots were deposited on silicon substrates by a hot filament process combined with laser heating. A mixture of CH4(1.8 vol%) and H2was passed over a tantalum filament having a temperature of about 2200 °C. The substrate temperature was varied by small adjustments of the filament power. A focused laser beam was used to locally raise the temperature on the substrate surface. By a proper choice of filament temperature, background substrate temperature and laser induced temperature, isolated islands of polycrystalline diamond could be deposited on the silicon substrate. The deposited diamond spots were characterized by micro-Raman spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and scanning force microscopy.

scholarly journals Influence of deposition parameters on mechanical properties of sputter-deposited Cr2O3 thin films

1999 ◽  
Vol 14 (9) ◽  
pp. 3623-3629 ◽  
Author(s):  
P. Hones ◽  
F. Lévy ◽  
N. X. Randall
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Scanning Force Microscopy ◽  
Silicon Substrates ◽  
Force Microscopy ◽  
Deposition Parameters ◽  
Scanning Force ◽  
Sputter Deposited ◽  
Substrate Hardness ◽  
Substrate Temperatures

Among the oxides, Cr2O3 exhibits the highest hardness value and a low coefficient of friction. These properties make chromium oxide an excellent coating material for tribological applications. Cr2O3 thin films were deposited by radio-frequency reactive magnetron sputtering at substrate temperature in the range 363–593 K. The hardness and elastic modulus of the films were measured by two complementary nanoindentation techniques to investigate the influences of the substrate temperature and the oxygen content in the sputtering gas. While the continuous stiffness data method provides information throughout the whole film thickness, nanoindentation combined with scanning force microscopy of the residual imprints allows visualization of pileup, cracking, and delamination from the substrate. Hardness values up to 32 GPa were obtained for substrate temperatures exceeding 500 K and oxygen contents between 15% and 25% of the total gas pressure. The films, obtained with these deposition conditions, showed good adhesion to silicon substrates.

Measurement of The Activation Energy in Phosphorous Doped Polycrystalline Diamond Thin Films Grown on Silicon Substrates by Hot Filament Chemical Vapor Deposition

1996 ◽  
Vol 423 ◽  
Author(s):  
S. Mirzakuchaki ◽  
H. Golestanian ◽  
E. J. Charlson ◽  
T. Stacy
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Silicon Substrates ◽  
Boron Doped Diamond ◽  
Diamond Thin Films ◽  
Hot Filament

AbstractAlthough many researchers have studied boron-doped diamond thin films in the past several years, there have been few reports on the effects of doping CVD-grown diamond films with phosphorous. For this work, polycrystalline diamond thin films were grown by hot filament chemical vapor deposition (HFCVD) on p-type silicon substrates. Phosphorous was introduced into the reaction chamber as an in situ dopant during the growth. The quality and orientation of the diamond thin films were monitored by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Current-voltage (I-V) data as a function of temperature for golddiamond film-silicon-aluminum structures were measured. The activation energy of the phosphorous dopants was calculated to be approximately 0.29 eV.

Growth of (100) oriented diamond grains by the application of lateral temperature gradients across silicon substrates

2004 ◽  
Vol 19 (11) ◽  
pp. 3206-3213 ◽  
Author(s):  
E. Titus ◽  
D.S. Misra ◽  
Manoj. K. Singh ◽  
Pawan. K. Tyagi ◽  
Abha Misra ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Film Deposition ◽  
Temperature Gradients ◽  
Diamond Surface ◽  
Silicon Substrates ◽  
Oriented Growth ◽  
Oriented Samples ◽  
Diamond Grain

Polycrystalline diamond films with a predominant (100) texture were deposited onto silicon substrates using hot-filament chemical vapor deposition. During film deposition, different temperature gradients were created and imposed laterally across the substrate materials. Films grown under a gradient of 100 °C cm−1 displayed large (100) oriented grains. No crystallite (100) orientation was observed in the as-grown films prepared without a temperature gradient. It was observed that the diamond grain size varied as a function of the gradient. The lower gradient resulted in smaller grains and vice versa. Furthermore, the size of the grains was a function of the deposition time. The orientation of the diamond grains changed gradually across the substrate from (100) to (110) orientation as we scanned from the high-temperature to the low-temperature zone. The films were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier transform infrared (FTIR) spectroscopy. XRD showed strong (400) reflections in the oriented samples. SEM results indicated the presence of smooth diamond surfaces consisting of predominantly (100) oriented platelets. As the (100) oriented diamond grains were grown on top of the (100) oriented silicon substrates, the faces were mostly aligned parallel to the substrate surface resulting in the deposition of a smooth diamond surface. AFM observations revealed the presence of steps located at the boundaries of the oriented grains. FTIR results showed the characteristic difference in hydrogen bonding in the oriented samples and gave useful information about mechanisms responsible for the orientation. Quantitative analysis was carried out to measure the H content in the films, and it was found that the oriented films contained less hydrogen. Our findings suggest that high saturation of carbon and a concentration gradient of sp3 CH2 species can be the key factor in the oriented growth of (100) diamond grains.

Effects of Substrate Bias on the Nucleation of Diamond Films Studied by Atomic Force Microscopy

1995 ◽  
Vol 416 ◽  
Author(s):  
G. Sánchez ◽  
M. C. Polo ◽  
W. L. Wang ◽  
J. Esteve
Keyword(s):  
Atomic Force Microscopy ◽  
Chemical Vapor ◽  
Nucleation Density ◽  
Silicon Substrates ◽  
Substrate Bias ◽  
Applied Bias ◽  
Force Microscopy ◽  
Nucleation Stage ◽  
Atomic Force ◽  
Hot Filament

ABSTRACTThe nucleation stage of diamond on silicon substrates was studied by atomic force microscopy. Samples were grown by hot filament chemical vapor deposition and substrate biases from -200 ν to +75 ν were investigated. The effects of the process on the substrate as well as on the morphology of the crystallites were observed using an atomic force microscope operating in tapping mode. It was observed that both the density and morphology of the diamond crystallites were greatly dependent on the applied bias values. The highest nucleation density was achieved for the -200 ν bias, when a plasma around the substrate holder was formed.

Electrical Properties of Fine Grain Composite Carbon Films

1992 ◽  
Vol 242 ◽  
Author(s):  
Hsiung Chen ◽  
R. O. Dillon
Keyword(s):  
Electrical Properties ◽  
Amorphous Carbon ◽  
Composite Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Carbon Films ◽  
Average Roughness ◽  
Force Microscopy ◽  
Fine Grain ◽  
Hot Filament

ABSTRACTWe have studied the electrical properties of boron doped composite films that consist of diamond and amorphous carbon. These films were deposited by hot filament chemical vapor deposition at a relatively high carbon/hydrogen ratio. The mixture of trimethyl borate vapor, and methane served as a source gas. The composite films had much smoother surfaces than polycrystalline diamond films.The surface morphology and average roughness were determined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Raman spectroscopy and x-ray diffraction were used to analyze the structure of the films.A composite film grown with 4% methane in hydrogen had a higher resistivity than a well faceted diamond film grown at 0.5% methane. In contrast to hydrogenated amorphous carbon films which have a lower resistivity after thermal annealing, the resistivities of composite films increased by a factor of two to ten after 3 hours annealing at 600°C.

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).

Scanned tip measurement of deep vertical facets on a flat surface: Measuring roughness on gaas laser waveguide mirrors

1993 ◽  
Vol 51 ◽  
pp. 532-533
Author(s):  
Chang Shen ◽  
Phil Fraundorf ◽  
Robert W. Harrick
Keyword(s):  
Integrated Circuits ◽  
Flat Surface ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Optoelectronic Integrated Circuits ◽  
Laser Waveguide ◽  
Scanning Force ◽  
Gaas Laser

Monolithic integration of optoelectronic integrated circuits (OEIC) requires high quantity etched laser facets which prevent the developing of more-highly-integrated OEIC's. The causes of facet roughness are not well understood, and improvement of facet quality is hampered by the difficulty in measuring the surface roughness. There are several approaches to examining facet roughness qualitatively, such as scanning force microscopy (SFM), scanning tunneling microscopy (STM) and scanning electron microscopy (SEM). The challenge here is to allow more straightforward monitoring of deep vertical etched facets, without the need to cleave out test samples. In this presentation, we show air based STM and SFM images of vertical dry-etched laser facets, and discuss the image acquisition and roughness measurement processes. Our technique does not require precision cleaving. We use a traditional tip instead of the T shape tip used elsewhere to preventing “shower curtain” profiling of the sidewall. We tilt the sample about 30 to 50 degrees to avoid the curtain effect.

Log-log scale roughness spectroscopy of surfaces

1993 ◽  
Vol 51 ◽  
pp. 224-225
Author(s):  
P. Fraundorf ◽  
B. Armbruster
Keyword(s):  
Power Spectrum ◽  
Autocorrelation Function ◽  
Power Spectra ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Scanning Force ◽  
Lateral Structure ◽  
Scale Roughness

Optical interferometry, confocal light microscopy, stereopair scanning electron microscopy, scanning tunneling microscopy, and scanning force microscopy, can produce topographic images of surfaces on size scales reaching from centimeters to Angstroms. Second moment (height variance) statistics of surface topography can be very helpful in quantifying “visually suggested” differences from one surface to the next. The two most common methods for displaying this information are the Fourier power spectrum and its direct space transform, the autocorrelation function or interferogram. Unfortunately, for a surface exhibiting lateral structure over several orders of magnitude in size, both the power spectrum and the autocorrelation function will find most of the information they contain pressed into the plot’s origin. This suggests that we plot power in units of LOG(frequency)≡-LOG(period), but rather than add this logarithmic constraint as another element of abstraction to the analysis of power spectra, we further recommend a shift in paradigm.

Anisotropy of Nanoindentation – a tool for the determination of nanocrystal orientation ?

2003 ◽  
Vol 779 ◽  
Author(s):  
David Christopher ◽  
Steven Kenny ◽  
Roger Smith ◽  
Asta Richter ◽  
Bodo Wolf ◽  
...  
Keyword(s):  
Crystal Surface ◽  
Scanning Force Microscopy ◽  
Depth Range ◽  
Dislocation Loops ◽  
Force Microscopy ◽  
Pile Up ◽  
Out Of Plane ◽  
Scanning Force ◽  
Dynamics Simulations

AbstractThe pile up patterns arising in nanoindentation are shown to be indicative of the sample crystal symmetry. To explain and interpret these patterns, complementary molecular dynamics simulations and experiments have been performed to determine the atomistic mechanisms of the nanoindentation process in single crystal Fe{110}. The simulations show that dislocation loops start from the tip and end on the crystal surface propagating outwards along the four in-plane <111> directions. These loops carry material away from the indenter and form bumps on the surface along these directions separated from the piled-up material around the indenter hole. Atoms also move in the two out-of-plane <111> directions causing propagation of subsurface defects and pile-up around the hole. This finding is confirmed by scanning force microscopy mapping of the imprint, the piling-up pattern proving a suitable indicator of the surface crystallography. Experimental force-depth curves over the depth range of a few nanometers do not appear smooth and show distinct pop-ins. On the sub-nanometer scale these pop-ins are also visible in the simulation curves and occur as a result of the initiation of the dislocation loops from the tip.

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