XPS-investigations on laser-modified Si3N4 ceramics

For the ultimate use of micro machining in technology the interaction of laser light and silicon nitride ceramic have been studied. Using X-ray photoelectron spectroscopy (XPS), different effects generated by radiation from Nd:YAG (free running mode) and excimer lasers have been observed. With the Nd:YAG laser (lambda = 1.06 mu m), reaction zone depths of several 100 nm, apparently caused by melting, were found. The excimer laser treatment with a lower penetration depth of the light (lambda = 248 nm) led to very low chemical surface damage. Thus the excimer laser is favored for exact micro machining of nitride ceramics.