LSI、VLSI正以飞快的速度向微细化、高集成化方向发展着,目前已从批量生产的64K位DRAM向256KDRAM逼近。随着设计规划的缩小,将光掩模(以下简称掩模)图形转印到硅片上的光刻方法也正从接触式曝光向投影式曝光乃至缩小投影的步进曝光方式迅速变化着。 LSI, VLSI is rapidly moving toward miniaturization, highly integrated direction, has now been from mass production of 64K DRAM to 256KDRAM approximation. With the reduction of design planning, the photolithographic method of transferring a photomask (hereinafter referred to as a mask) pattern onto a silicon wafer is rapidly changing from a contact exposure to a projection exposure and even a stepwise exposure reduction projection.