APPARATUS FOR, AND METHOD OF, EXPOSING A PHOTOSENSITIVE MEDIUM TO LIGHT

摘要

In an optical lithography method and apparatus, a light source (10) comprises a pulsed rare gas halide excimer laser which produces light having at least one fundamental wavelength. The output of the light source (10) is directed by an optical system (12) to expose a photosensitive medium (16). The output of the laser is highly non-gaussian and has sufficient power so that full exposures can be accomplished within a few seconds. An alternative light source is provided by directing the excimer laser output to a Raman cell having a suitable Raman medium contained therein. At least one secondary wavelength is produced by stimulated Raman scattering and the output of the Raman cell is directed to expose a photosensitive medium. A mixture of more than one excimer gas can also be provided in the excimer laser to produce one fundamental output for each excimer gas present in the mixture. These outputs can be directed to expose a photosensitive medium directly. Alternatively, these outputs can be directed to a Raman cell having either a single Raman medium or multiple Raman media in a suitable mixture and directing the output from the Raman cell to expose the photosensitive medium.