Silicon carbide films

Chemical and phase purity are not always desirable. For example, H- and N-doped silicon carbide films behave as high temperature semiconductors, while silicon carbonitride glasses offer properties akin to glassy carbon with room temperature conductivities of 103 2 cm-118. Additional reasons for targeting materials that are not chemically or phase pure stem from the desire to control microstructural properties. 

Park, J-W., et al. (2007), Effects of Ion Beam Mixing of Silicon Carbide Film Deposited onto Metallic Materials for Application to Nuclear Hydrogen Production ,/, of Nucl. Materials, 362, 268-273. 

Kerdihes S., Rizk R., Gourblleau F., Perez-Rodriguez A., Garrido B., Gonzalez-Varona O. and Morante J. R., Low temperature direct growth of nanocrystalline silicon carbide films, Mater. Sci. Eng. B 69 (2000) pp.530-535. 

In, the central zone, the regular distribution of transverse cracks shows that the induced strain is rather homogeneous. Consequently, many analytical models can be applied in order to determine the intrinsic parameters of the coatings. The critical cracking energy and the mode I fracture toughness of the deposited silicon carbide film were assessed by means of the model presented previously. It should be remembered that it was first established and developed for composite materials based on research by Kelly and subsequently by Hu ", that when the stress normal to the coating reaches a critical value... 

Since it is the products of the gas phase reactions and not the reagents fed into the chemical reactor that serve as actual deposition precursors, this observation suggests that the occurrence of any chemical reactions in the entry section of the reactor (before the isothermal hot zone) may have significant effects on the deposition rate profile within the isothermal zone. Silicon carbide films... 

K. Chew, Rush, S.F. Yoon, J. Ahn, Q. Zhang, V. Ligatchev, E.J. Teo, T. Osipowicz and F. Watt, Gap state distribntion in amorphous hydrogenated silicon carbide films deduced from photothermal deflection spectroscopy, J. Appl. Phys., 91(7), 4319-A325, 2002. 

Figure 19.25 High-resolution AFM images of silicon carbide films deposited at (a) BOOK and (b) 1323 K together with their 2D pair distance distribution (c,d). Note the incipient ordering into atomic rows of the 1323 K film (From Ref [59]).

Davis, R., Silicon Carbide and Diamond Semiconductor Thin Films, M/w. Ceram. Soc. Bull, 72(7) 99-106(July 1993)... 

CVD is a maj or process in the production of thin films of all three categories of electronic materials semiconductors, conductors, and insulators. In this chapter, the role of CVD in the fabrication of semiconductors is reviewed. The CVD production of insulators, conductors, and diffusion barriers is reviewed in the following chapter. The major semiconductor materials in production or development are silicon, germanium, ni-V and II-VI compounds, silicon carbide, and diamond. 

As these experiments indicate, polysilanes can in some cases be converted to silicon carbide directly, without the necessity for formation of polycarbosilane, fractionation, or oxidation. For example, polysilastyrene copolymers can be formed into films or fibers and then crosslinked by irradiation with UV light. The crosslinked polysilane forms silicon carbide when heated to 1100°C in vacuum. (1U This method can be used in a "printing" mode, if a film of polysilane is cast onto a ceramic or metal substrate, then... 

Apart from the reactions described above for the formation of thin films of metals and compounds by the use of a solid source of the material, a very important industrial application of vapour phase transport involves the preparation of gas mixtures at room temperature which are then submitted to thermal decomposition in a high temperature furnace to produce a thin film at this temperature. Many of the molecular species and reactions which were considered earlier are used in this procedure, and so the conclusions which were drawn regarding choice and optimal performance apply again. For example, instead of using a solid source to prepare refractory compounds, as in the case of silicon carbide discussed above, a similar reaction has been used to prepare titanium boride coatings on silicon carbide and hafnium diboride coatings on carbon by means of a gaseous input to the deposition furnace (Choy and Derby, 1993) (Shinavski and Diefendorf, 1993). 

The ultrafine silicon carbide produced in an electric arc is used as an insulation in cryogenic applications (152) (see Cryogenics). It generally increases the wear resistance of the paint film when added to paint formulations. 

Silicon-based materials (silicon carbide, silicon nitride) usually form a superficial film of silicon dioxide that protects the material against corrosion in acidic or neutral media. At pH equal to or higher than eleven it suffers corrosion heavily because the silicon dioxide is dissolved [25],... 

Coated abrasives consist of a flexible backing on which films of adhesive hold a coating of abrasive grains. The backing may be paper, cloth, open-mesh cloth, vulcanized fiber (a specially treated cotton rag base paper), or any combination of these materials. The abrasives most generally used are fused aluminum oxide, sol-gel alumina, alnmina-zirconia. silicon carbide, garnet, emeiy, and flint. 

HRTEM observations of three differently misoriented interphase boundaries between hexagonal boron nitride (h-BN) and 3C silicon carbide (3C SiC) grains showing an orientation dependence on equilibrium film thickness. In (a) and (b) the (0001) of the highly anisotropic b-BN are parallel to the interface, whereas in (c) they make an angle of 68° with the interphase boundary (reprinted from Ultramicroscopy, Knowles KM and Turan S, The dependence of equilibrium film thickness on grain orientation at interphase boundaries in ceramic-ceramic composites, 83(3/4) 245-259 (2000) with kind permission of Elsevier Science). 

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