Laser-assisted etching of the surface of polycrystalline silicon carbide by copper-vapour laser radiation

摘要

An investigation was made of laser-assisted (by radiation from a copper vapour laser) etching of polycrystalline silicon carbide in air and in liquid media (water, dimethyl sulfoxide). The maximum etching rate of ceramic SiC in air reached 0.24 mm pulse-1 and in dimethyl sulfoxide it was 0.07 mm pulse-1 when the energy density was 16 J cm-2 in both cases. Scanning electron microscopy and x-ray structure analysis were used to study changes in the morphology and chemical composition of the etched surface of SiC. Etching in air produced partly amorphised silicon carbide and microcrystals of free Si with a characteristic size of about 30 nm. The surface of silicon carbide subjected to laser-assisted etching was capable of chemical reduction of copper from a solution used for chemical metallisation. Copper coatings formed in this way adhered strongly to the surface (adhesion force up to 30 N mm-2).