Patent ID: 8823921
Filing Date: 2014-09-02
Classification: G02B,G03F

Abstract:
1. A photolithography system for illuminating over an optical path a reticle having a reticle field to form one or more exposure fields on a wafer having a surface, an edge and a coating of photoresist that includes an annular edge portion adjacent the wafer edge, comprising: a light source that generates actinic light; a first optical system configured to receive the actinic light from the light source, the first optical system having at least one uniformizing element configured to form uniformized actinic light from the received actinic light; a programmable micro-mirror device having an array of micro-mirrors, with each micro-mirror having an adjustable orientation, the programmable micro-mirror device being arranged to receive and selectively reflect the uniformized light according to a select configuration of orientations of the adjustable micro-mirrors; a control unit operably connected to the programmable micro-mirror device and configured to control the orientations of one or more of the adjustable micro-mirrors; a second optical system arranged to receive the selectively reflected uniformized light along the optical path and to form an illumination field that illuminates the reticle field; a projection lens operably disposed between the reticle and the wafer, the projection lens serving to image the one or more exposure fields in the photoresist based on the illuminated reticle field, wherein the one or more exposure fields include at least one edge exposure field that would at least partially overlap the annular edge portion of the photoresist if the reticle field were fully illuminated; and wherein the control unit controls the select orientation of the micro-mirrors of programmable micro-mirror device to partially illuminate the reticle so that no portion of the edge exposure field extends into the annular edge portion of the photoresist.