Electron diamond films

Eden, R. C., Application of Synthetic Diamond Substrate for Thermal Management of High Performance Electronic Multi-Chip Modules, in Applications of Diamond Films and Related Materials, (Y. Tzeng, etal., eds.), Elsevier Science Publishers, pp. 259-266(1991)... 

Figure 5.5. Electron micrographs of different types of diamond film grown on silicon. The white bar shows the scale in micrometres (p.m) (thousandths of a millimetre), (a) The initial stages of diamond growth on a nickel substrate, showing individual diamond crystallites nucleating in scratches and crevices created on the surface by mechanical abrasion, (b) a randomly oriented him,...

A.H. Deutchman and R.J. Partyka (Beam Alloy Corporation observe, "Characterization and classification of thin diamond films depend both on advanced surface-analysis techniques capable of analyzing elemental composition and microstructure (morphology and crystallinity), and on measurement of macroscopic mechanical, electrical, optical and thermal properties. Because diamond films are very thin (I to 2 micrometers or less) and grain and crystal sizes are very small, scanning electron microscopy... 

Diamond Hints, although not approaching bulk diamond, are harder than most refractory nitride and carbide thin films, which makes them attractive for tribological coatings. Transparency in the visible and infrared regions of the optical spectrum can be maintained and index-of-refraction values approaching that of bulk diamond have been measured. Electrical resistivities of diamond films have been produced within the full range of bulk diamond, and thermal conductivities equivalent to those of bulk diamond also have been achieved. As substrates for semiconductor electronic devices, diamond films can be produced by both the PACVD and IBRD techniques. 

Figure 10.1 Scanning electron microscope image of a roughly 10 /rm thick CVD diamond film exposing its (001) facets at the top. The image was kindly provided by X. Jiang [414].

Photoelectrochemical measurements also provide an approach to the determination of electrophysical characteristics of diamond. In addition to the threshold energies of electron phototransitions, determined by the analysis of the photocurrent action spectra (Section 7), the diffusion length of minority carriers in polycrystalline diamond films was estimated (at 2 to 4 pm) by comparing light absorption spectra and open-circuit potential spectra [171],... 

Figure 45 Auger electron spectra (AES) of a hydrogen-terminated boron-doped diamond film supported on a diamond made (see text for details). (From Ref. 67.)...

Figure 1. Connectivities and principle bonding properties of carbon. From top to bottom connectivity, chemical bonding representation, distribution of n electrons, hybridization symbol, bond length, orientation of the n bonds relative to the carbon skeleton. The spectra represent polarization-dependent carbon 1 s XAS data for sp2 and sp3 carbons. The angles denote the orientation of the E vector of the incident light relative to the surface normal of the oriented sample. The assignment of the spectral regions is given and was deduced from the angular dependence of the intensities of each feature. The graphite impurity in the CVD diamond film is less than 0.1 monolayers.

There are some disadvantages for HFCVD method. Filament is relatively easy to break, and its life time is around 100 h. Second, due to the high working temperature, the filament metal element can evaporate into the gas phase and deposit in the diamond film, which is a kind of contamination (Venter and Neethling 1994). Mehta Menon s group reported that tungsten filament yielded the lowest impurity level (few ppm by mass), whereas rhenium yielded the highest (parts per thousand) (Mehta Menon et al. 1999). Metal contamination in the diamond would affect the electronic application of diamond, even in ppm level, but this is not a big problem for the electrochemical application. 

A high-quality diamond film electrode needs high purity and quality diamond film fully covering the substrate to limit the exposure of the substrate to the environment. Micro-Raman spectroscopy, X-ray diffraction (XRD), and scanning electron... 

Single pulse, shock tube decomposition of acetic acid in argon inv olves the same pair of homogeneous, molecular first-order reactions as thermolysis (19). Platinum on grapliite catalyzes the decomposition at 500—800 K at low pressures (20). Ketene, methane, carbon oxides, and a variety of minor products are obtained. Photochemical decomposition yields methane and carbon dioxide and a number of free radicals, wliich have complicated pathways (21). Electron impact and gamma rays appear to generate these same products (22). Electron cyclotron resonance plasma made from acetic acid deposits a diamond [7782-40-3] film on suitable surfaces (23). The film, having a polycrystalline stmcture, is a useful electrical insulator (24) and widespread industrial exploitation of diamond films appears to be on the horizon (25). 

Heteroepitaxy of diamond on c-BN has been successful (e.g., 105,106) due to the identical crystal stractures with a close lattice match (only 1.3% mismatch) between the two and the high surface energy ( 4.8 J/m ) of the c-BN (111) plane. The heteroepitaxy of diamond on silicon could be the key to electronic device apphcations of diamond. However, diamond has a large lattice mismatch with silicon (52%) and a much higher surface energy than silicon (6 J/m for diamond, 1.5 J/m for silicon), hi spite of this, there are several reports of oriented diamond film deposition on substrates like silicon, silicon carbide, etc., by various techniques (e.g., 108-112). 

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