Large-area high-quality photomasks

摘要

Abstract: The LRS family of laser scanning pattern generators with stages 600 by 600, 800 by 800, and 1100 by 1100 mm, a selection of optical resolutions, and lasers for chrome and photographic emulsion cover the complete range of precision large-area masks. The first large-area system was delivered in 1992, and there are now 11 systems installed or on order for applications ranging from precision metal etching to shadow masks and high-end chrome masks for AMLCDs and field-effect displays. These writers match the requirements for the next generation of large screen printers. It is technically feasible to build a full-field projection printer with resolution and geometrical corrections similar to those of a stepper, but with no stitching or intra-field distortion. The pattern quality would be that of the mask and higher productivity would result. The combined experience of masks for flat panels and shadow masks makes the LRS system well characterized for visual display applications. In particular all systematic errors visible in the finished displays are suppressed to very low levels. The LRS writers satisfy the needs for high-quality large-area photomasks, including masks for AMLCDs. !5