Reticle exposure apparatus and method

Abstract

An apparatus and method are described for applying a light beam in an extremely precise pattern to a work piece, such as a photographic plate or reticle on which an integrated circuit pattern is to be formed and which will be then utilized to produce integrated circuits. The method includes moving a very narrow beam light source relative to the reticle in a scanning pattern such as an X-Y raster pattern, accurately sensing the relative positions of the light source to the reticle as by the use of laser interferometers, and briefly energizing the light source only when it lies at the locations to be exposed. The light source is energized while it moves, so it is not necessary to stop the light source at precisely located positions. The light source can be moved relative to the reticle, by mounting the light source on a flexible plate that oscillates in substantially a straight line, and by mounting the reticle on another flexible plate that moves perpendicular to the light source and that can be very slowly advanced perpendicular to the oscillating light source, so that after a period of time the light source has moved over every point of the reticle, although only a minority of the points normally will have been exposed.