Large-area, scan-and-repeat, projection patterning system with unitary stage and magnification control capability

摘要

In numerous applications of large-area patterning systems, the preferred image magnification is unity. However, in some applications, the size of the substrate may change slightly due to various thermal and/or chemical processing steps. To compensate for scale changes of the substrate, the magnification of the imaging system must vary slightly from unit magnification (typically by a fraction of a percentage) so that a layer already patterned on the substrate will have, after processing, proper image registration with the subsequent layer.PP This disclosure describes a lithography system for exposing large substrates at high imaging resolution and high exposure throughput, and specifically relates to a scan-and-repeat patterning system that employs a unitary mask-substrate stage and enables projection imaging of a substrate with capability to control the image magnification to compensate for changes of substrate dimensions occurring as a result of previous process steps.PPA combination of optical and mechanical compensation is used to provide the necessary magnification control, including anamorphic magnification variation in which the fine adjustment is of different magnitudes in x and y dimensions. The optical control is provided by a projection lens with anamorphic magnification adjustment capability. The mechanical compensation is performed by providing a differential relative velocity between the mask and substrate during scanning.