NITROGEN-RICH SILICON-NITRIDE THIN-FILMS FOR DEEP-ULTRAVIOLET MIRAU INTERFEROMETRY

We report experimental results on W-transparent low-pressure chemical- vapor-deposition nitride thin films, We show that, by using nitrogen-r ich rather than conventionally silicon-rich thin-film membranes, we ar e able to obtain more than 95% UV transparency below 250 am, while kee ping the stress of the membrane manageable and below standard nitride' s giga-Pascal stress. Using these results, we were able to microfabric ate a UV Mirau interferometer for correlation microscopy. (C) 1997 Opt ical Society of America.