Localized plasma assisted chemical etching through a mask

摘要

A system for the formation of circuit patterns on a large flat panel display (78) using plasma assisted chemical etching to achieve a uniform or controllably nonuniform etch depth over the entire area of the display. An overlying film (60) is provided on a large flat panel display substrate (12) with a photolithographic mask (62) overlying the film and having a predetermined pattern of openings (64) therethrough. The substrate is placed adjacent a plasma etching tool which has a projected area which is smaller than the area of the surface of the substrate. The etching tool is scanned across the surface of the substrate to transfer the pattern of the photolithographic mask into the film on the surface thereof. Thereafter, the photolithographic mask is removed from the surface of the overlying film. It is desirable to determine thickness profile data for the overlying film, then generate a dwell time versus position map for the overlying film and remove material from the exposed regions of the overlying film according to the dwell time versus position map. The substrate may be glass and the film may be silicon in either the amorphousr or polycrystalline states.