LASER PROCESSING OF DIAMOND FILMS

A review of the use of lasers for the cutting, patterning, polishing a nd metallization of diamond is presented. The discussion focusses main ly on chemical vapor-deposited (CVD) polycrystalline diamond films, ho wever, in some cases results for natural and synthetic single crystal diamonds are also given for comparison. The laser processing is based on the ability of local heating and ablation of a material by a high-i ntensity light flux. Damage thresholds and etch rates of diamonds of d ifferent grades are compared for lasers operated in a broad range of w avelengths and pulse durations. Examples of various patterns etched in diamond by laser ablation using the direct writing technique are give n. Special attention is paid to the laser smoothing of rough as-grown surfaces of CVD diamond since this technique allows a surface finish b elow 100 nm to be achieved. A novel method of selective-area diamond m etallization by electroless deposition of Ni and Cu on a laser-activat ed diamond surface is described. Other examples of laser applications considered include selective-area diamond deposition, diamond engravin g by laser-assisted burning, defect annealing, uniform seeding of the substrate with diamond nucleation centers, and improvement of diamond film adhesion.