This paper describe the growth of a transparent SiO2 thin film performed by using Xe2• excimer lamp at room temperature. In this study, NF., and O2 mixture gases was employed as a reaction gas. A silicon substrate was placed in a reaction chamber, which was filled with NF3 and O2 mixture gases. The mixture gases were exposed to the Xe2• excimer lamplight, and SiF4 and NO2 gases were produced by photochemical reaction. Subsequently SiF4 adsorbed onto the Si substrate. SiO2 was formed by oxidation reaction between SiF4 and NO2. These processes occur spontaneously, and SiO2 film is grown. The refractive index of fabrication SiO2 thin film is 1.32. By annealing at 200°C, the refractive index of this filn was increased to 1.44. Further increase in the annealing temperature, resulted in a higher refractive index and lower density of fluorine atoms.

We review for diamond-like carbon the various deposition methods, the deposition mechanisms of subplantation and ion-assisted addition, the characterisation methods such as Raman and electron energy loss spectroscopy, its mechanical properties and some applications as a coating material.

We have prepared diamondlike carbon (DLC) films using KrF excimer pulsed laser (248 nm). The DLC films were deposited on Si (100) substrates and Cu and Ti were incorporated into the films through adopting a new target design. Visible Raman spectroscopy analysis of G-peak was correlated to internal stress changes in the DLC films due to incorporation of foreign atoms. Reduction of internal stresses in the presence of foreign atoms was established. This is consistent with adhesion studies that showed significant improvement in adhesion of DLC films containing dopants. Nanohardness and Young's modulus of DLC films containing Ti and Cu showed some decrease as compared to pure DLC. The experimental results are discussed in terms of the effect of dopants on the short range environment of the continuous random network (CRN) of DLC.

Diamond-like nanocomposite (DLN) film, by embedding the diamond-like carbon into an amorphous SiO2 network, is a special class of modified diamond-like carbon (DLC) coating, which shows many excellent properties and potential applications. In this work, DLN films were fabricated in an acetylene atmosphere by ion beam assisted deposition. However, in order to understand the mechanical and electronic properties of the DLN film separation of the sp3 carbon bond from sp2 bond is necessary, because the former determines the hardness and the latter is related to the optical gap and electrical conductivity. Here we report the effect of the annealing on the relative concentrations of sp3 and sp2 hybrids in the film by using the XPS technique to decompose the C ls signal into sp3 and sp2 components. The XPS results clearly indicate that the distribution of the sp3 and sp2 C species is modified by thermal annealing at 700 °C. More sp3 species accumulate at the interface and gradually decrease towards the film surface.

Amorphous hydrogenated carbon thin films have been deposited from benzene vapor in a microwave electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition (CVD) system. Plasma enhanced dissociation and reaction of benzene were monitored by mass spectrometry. Deposited films were characterized by Fourier transform infrared spectroscopy and fluorescence spectroscopy. The effect of the deposition rate on the film density and plasma etch resistance was also studied. The etch resistance of deposited carbon film is higher than the conventional resist Novolac.

The surface and gas-phase kinetic of deposition of diamond-like carbon films (DLC) obtained in plasma reactors using methane as precursor was here investigated. Kinetic constants of electronic reactions were evaluated using experimental ionization and neutral dissociation cross sections and the Druyvestein electron distribution function. Kinetic constants for ionic and neutral reactions were found in the literature. Surface reactions were divided into processes involving the impingement of gas-phase radicals or ions from the plasma and desorption or recombination reactions of adsorbed surface species. The kinetic constants of the former processes were evaluated.from the ambipolar theory or from the kinetic theory of gases, while the other kinetic constants were determined from analogy with hydrocarbon chemistry. The exception is the desorption of adsorbed methyl radicals, whose kinetic constant was fitted over experimental data. The predictivity of the model was tested through the simulation of three reactors described in the literature widely differing for operating conditions.

We report on Raman studies of diamond-like carbon (DLC) films; in particular, we report on the instrumentation and methodology required for comparing Raman measurements taken on different Raman analyzers. Raman spectroscopy has taken on an increasingly important role in materials processing because of its capability of performing non-destructive, in situ characterization of thin films. In particular, noncrystalline carbon coatings have become ubiquitous as protective layers on everything from machine tools to hard disk drives. As tolerances on coating properties begin to play an important part in determining device failure, Raman spectroscopy has found ever greater application as a quality control/quality assurance tool. However, use of Raman as an analytical tool has been hampered by the inability to quantitatively compare spectra obtained with different Raman analyzers. By using automated, robust calibration protocols on both the wavelength and intensity axes, we have demonstrated cross-instrument calibration transfer of DLC films.

Diamond films were grown heteroepitaxially on iridium (100) substrates by microwave plasma-assisted chemical vapor deposition (MPCVD) using methane gas as the carbon source. The iridium substrate, which was formed on a MgO (100) substrate by means of sputtering at 850 °C, was treated by imposing a negative bias between -150 and -200 V for 15 min. Methane concentration and substrate temperature were maintained at 3° and 650–740 °c, respectively. At a substrate temperature of 740 °C, diamond particles were formed at a population density of (0.15- 1.5)x108 cm-2, and most of them were oriented to MgO (100). After a further reaction for 1 h under conditions which were optimized for diamond growth, the oriented diamond particles were coalesced, and islands of (100) diamond were formed.

The diamond-like carbon (DLC) films added with silicon content from Oat% to 19.2at% were deposited using R.F. PECVD. By increasing the annealing temperature the groups of CHn and Si-H in FTIR spectra of the deposited films decrease because of hydrogen evolution, whereas the intensity of C=O and Si-O peaks increases due to oxidation. From Raman spectra, the observable shoulder of D band occurs at 400°C and 500°C respectively, which indicates that the addition of silicon improves the thermal stability of DLC films. A pin-on-disk wear test was conducted to investigate the wear behavior of the DLC films. DLC film with small amount of silicon addition has a lower friction coefficient (0.01) than the undoped one(0.1). Raman analysis showed that in wear test the graphitization of pure DLC film occurs at the initial stage whereas for the silicon containing DLC, graphitization of wear debris or transferred film was not observed after the wear test.

Diamond-like carbon films (DLC) 10–40 nm thick were deposited on quartz substrates on an interdigitated planar array of 20 μm Ni electrodes already prepared by lithographic techniques. The influence of the adsorbed molecules onte electrical properties of the thin DLC films was investigated. Current and capacitance-voltage characteristics were examined. Charge-based deep level transient spectroscopy (Q-DLTS) was used for study of adsorption and desorption processes. The strong sensitivity of Q-DLTS spectra to the presence of the vapor water and isopropyl alcohol was found. For example, the Q-DLTS signal for some deposited DLC film was changed more then in order in presence of the water vapor. Such strong surface phenomena of the thin DLC films may be exploited in novel gas sensor devices.

Carbon-nitride and diamond-like-carbon films were deposited by electron cyclotron resonance chemical vapor deposition (ECR-CVD) using carbon precursors in either a nitrogenor an argon-high-density plasma. The carbon precursors were tetrachloroethylene (C 2C14), ethylene (C2H4) and neopentane (C5H12). Electron spectroscopy for chemical analysis (ESCA) and Fourier transform infrared (FTIR) spectroscopy showed three distinct chemical compositions: chlorine-doped carbon nitride (CNx:Cl), hydrogenated carbon nitride (CNx:H) and hydrogenated amorphous carbon (a-C:H). FTIR spectroscopy revealed a fourth composition: chlorine-doped amorphous carbon (a-C:Cl). ESCA analysis of the a-C:Cl film was not performed. Microstructures ranging from amorphous to microcrystalline were observed using differential interference contrast (DIC) optical microscopy and atomic force microscopy (AFM). Plasma etching of the substrate prior to film growth and biasing of the stage during film growth strongly influence the resulting microstructure. 100-μm-size, stacked, pyramidal CNx:Cl crystallites were deposited onto a glass microscope slide through a combination of substrate preetching and rf-biasing of the stage during film growth. In later experiments, pulsed-dc-highvoltage biasing of the stage during the growth process resulted in the deposition of 1-jim-size, rectangular- and triangular-shaped CNx:Cl crystallites onto fused silica.

Chlorinated instead of hydrogenated precursors were used to eliminate hydrogen incorporation during the growth of the ECR-CVD carbon nitride films. Chlorinated hydrocarbon precursors like trichloroethylene (C2HC13) and C2C14 reduce the amount of hydrogen in the plasma and make the formation of CN bonds more favorable. The results also show that doublebonded CC precursors are needed for N2 to react with carbon. However, when a hydrogenated precursor like C2H4 is used with a N2 plasma, hydrogen reacts with the CC double bond to form CH and NH bonds faster than N2 can react to form double- and single-bonded CN. The disadvantages of using chlorinated-carbon precursors are that the resulting CNx:Cl films contain a small amount of chlorine (Cl), are porous and are unstable with respect to moisture incorporation.

It is much easier to obtain stable, dense films using chlorinated precursors if more conventional materials are deposited. Silicon dioxide (SiO2) and silicon nitride (Si3N4) films were deposited by ECR-CVD using trichlorosilane (SiHC13). The films showed no degradation or moisture incorporation after several months.

A new synthesizing method, IR-laser-assisted electron-cyclotron-resonance plasma-enhanced chemical vapor deposition (LA-ECR-PECVD), has been used to fabricate Si-C-N and C-N films on steel substrates at low temperatures (< 650 °C). Methane/nitrogen or carbon dioxide/nitrogen gases are dissociated to methane radicals and nitrogen plasma by the IR-laser and ECR to enhance the species' energy. An IR-laser beam (pulsed Nd:YAG laser, 1064 nm) was introduced into the growth chamber for two purposes: (1) to add Si atoms by ablating a Si target, and (2) to enhance the plasma concentration in the gas phase. An infrared vibration mode located at 1256 cm-l wavenumber was observed in Si-C-N and C-N films, although these films have an amorphous phase. The C-N film also has a Raman shift at 1276 cm-l. The AFM images reveal many islands with a size ranging from 50 nm – 150 nm in films.

Boron nitride (BN) coatings are deposited by the reactive sputtering of fully dense, boron (B) targets utilizing an argon-nitrogen (Ar-N2) reactive gas mixture. Near-edge x-ray absorption fine structure analysis reveals features of chemical bonding in the B ls photoabsorption spectrum. Hardness is measured at the film surface using nanoindentation. The BN coatings prepared at low, sputter gas pressure with substrate heating are found to have bonding characteristic of a defected hexagonal phase. The coatings are subjected to post-deposition nitrogen (N+ and N2+) implantation at different energies and current densities. The changes in film hardness attributed to the implantation can be correlated to changes observed in the B ls NEXAFS spectra.

Microwave 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.

We examined the possibility of nucleation and growth of diamond via a hydrogen-free vapor phase route of pulsed laser ablation of a graphite target in a low-pressure pure oxygen atmosphere. The present evidences from microscopic, diffraction and spectroscopic techniques indicate that high-quality (111)-oriented diamond crystals could be nucleated and grown on ultra smooth sapphire (single-crystal α - A12O3)substrates at the temperatures lower than 600°C under the optimized growth conditions of oxygen pressure (around 0.15 Torn) and laser ablation (pulsed laser fluence of 3 x 108 W/cm2 at 5 Hz).

We have investigated the growth of carbon nitride (CNx) coatings on various substrates using laser assisted methods such as pulsed laser deposition (PLD) and laser chemical vapor deposition (LCVD). It has been shown that the both techniques produce good quality thin films of CNx. In PLD, a laser beam (λ= 248 nm) has been used to ablate the pyrolytic graphite target in nitrogen atmosphere, where as CO2 laser was used to irradiate carbon-nitrogen containing mixtures such as C2H2/N20/NH3 in LCVD method. A comparative analysis will be presented in terms of structural properties of CNx films prepared by both techniques.

Adherent diamond coatings up to ∼35 um thick have been grown by microwave plasma CVD (MPCVD) on sintered tungsten carbide (WC) substrates and their erosive wear properties investigated under high velocity air-sand erosion testing. Two different sintered tungsten carbide (WC) substrates have been investigated and compared, the binder being either 6%Co or 5%Ni by weight. Coating properties are sensitive functions of surface pre-treatment and deposition procedures. Adherent coatings offer significantly better erosion resistance compared to uncoated substrates, with the erosion rate being lower by up to a factor between ∼5 and 20 for particle test velocities of 148 ms-1 and 63 ms-1 respectively. Films with low residual stress appear to exhibit longer times to failure which tends to occur catastrophically along the coating-substrate interface.

We report the 13C NMR spectra of amorphous hydrogenated carbon and boron carbide. The amorphous hydrogenated carbon spectra consist primarily of a sp2 carbon peak at 40 ppm and a sp3 carbon peak at 140 ppm and are in reasonable agreement with recent theoretical calculations of Mauri, Pfrommer, and Louie, but there are some noteable discrepancies. The amorphous hydrogenated boron carbide spectra are very different from that of amorphous hydrogenated carbon, showing two sharp lines at 135 and 170 ppm at low boron concentrations and an intense, broader line at 15 ppm at high boron concentrations. We suggest the two sharp lines at 135 and 170 ppm could be due to carbon atoms in boron-containing aromatic rings, and the broader line at 15 ppm as due to carbon atoms in boron carbide icosahedra. These lines provide evidence of nanocrystalline structure imbedded in an amorphous hydrogenated boron carbide matrix.

Ti(C,N) hard coating is well known as a suitable material for protecting substrate, and functionally gradient design is a method to improve the performance of it. In this study, functionally gradient Ti(C,N) coatings were performed by the technique of capacitive RF PECVD based on the investigation of Ti(C,N) monolayers with different C and N ratios. The results show that the composition and growth rate of Ti(C,N) monolayers are influenced by the nitrogen/methane ratio as other deposition parameters are fixed. A model is also proposed from the results obtained and is employed to calculate the reaction gas ratio and duration time needed for deposition in the gradient coating. The elements of Ti and N in the gradient coatings were analyzed by Auger electron spectroscopy (AES) and revealed that the composition changed linearly as designed. The residual stress of the gradient coatings was also measured to show that the gradient design provides the possibility for adjusting the stress distribution of PECVD hard coatings.

Carbon nitride films raise current interest for their potential applications as ultrahard materials. We report on the formation of crystalline CN structures in films deposited at 248 nm on different substrates (sapphire, quartz, alumina) using the laser-induced CVD method and a gas mixture containing ethylene/nitrous oxide and ammonia as carbon and nitrogen source, respectively. The structural and morphological properties of the films were characterized by different analytical techniques (SEM, TEM, TED and XPS).