A photolithography tool, e.g. for microelectronics production, having the stage units (both mask and substrate stage units) composed of two identical stage assemblies which are simultaneously driven with the programmed production motions. The acceleration time histories of the stage assemblies within...http://www.google.com.au/patents/US7002668?utm_source=gb-gplus-sharePatent US7002668 - Stage positioning unit for photo lithography tool and for the like
