摘要 |
In a preferred embodiment room temperature electrically conductive or semiconductive ceramic paths or areas are produced on carbide and nitride ceramic substrates by a process of controlled oxidation using localized thermal heating (e.g., laser heating) by tracing desired paths onto the substrates, where air is the source of oxygen. In another embodiment, nitride and carbide ceramic substrates are converted to electroconductive or semiconductive ceramics where the substrate is characterized as whiskers, fibers, flakes or platelets whose dimensions are in the micron range, by controlled oxidation as prescribed by laser beam processing. The resulting conductive or semiconductive paths or surfaces of the substrate comprise electrically conductive or semiconductive nonstoichiometric aluminum-nitrogen-oxygen ceramic, when the initial ceramic substrate material is aluminum nitride(A1N); and electrically conductive or semiconductive nonstoichiometric silicon-carbon-oxygen ceramic, when the initial ceramic material used is silicon carbide (SiC). The path cut into the surface on a flat substrate can serve e.g. as electrical interconnects akin to printed circuitry on a wiring board and patterns of semiconductors formed can serve e.g. as semiconductive devices akin to rectifier devices. In the instance of the whiskers, fibers, flakes or platelets, the electrically conductive surfaces thereof may be used directly or enhanced for example, by coating other conductor metal or alloys onto the surface for uses e.g. as composite materials in matrices at the microstructural level.
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