Controlled pulse-etching with xenon difluoride

A gas-phase, room-temperature, plasmaless isotropic etching system has been used for bulk and thin film silicon etching. A computer controlled multi-chambered etcher is used to provide precisely metered pulses of xenon difluoride (XeF/sub 2/) gas to the etch chamber. Etch rates as high as 15 microns per minute have been observed. The etch appears to have infinite selectivity to many common thin films, including silicon dioxide, silicon nitride, photoresist, and aluminum. The etch rate, profile, and roughness are reported as a function of mask aperture, etch pressure, and duration.