Abstract: Characterization of an optical system is quickly and easily obtained in a single acquisition step by obtaining image data within a volume of image space. A reticle and image plane are positioned obliquely with respect to each other such that a reticle having a plurality of feature sets thereon, including periodic patterns or gratings, is imaged in a volume of space, including the depth of focus. Metrology tools are used to analyze the detected or recorded image in the volume of space through the depth of focus in a single step or exposure to determine the imaging characteristics of an optical system. Focus, field curvature, astigmatism, spherical, coma, and/or focal plane deviations can be determined. The present invention is particularly applicable to semiconductor manufacturing and photolithographic techniques used therein, and is able to quickly characterize an optical system in a single exposure with dramatically increased data quality and continuous coverage of the full parameter space.

Abstract: The present invention includes a lithography system comprising a lithography patterning chamber, a wafer exchange chamber separated from the lithography patterning chamber by a first gate valve, and at least one alignment load-lock separated from the wafer exchange chamber by a second gate valve. The alignment load-lock includes an alignment stage that aligns a wafer during pump-down. An alignment load-lock according to the present invention can be uni-directional or bi-directional. Likewise, a lithography system according to the present invention can include one or multiple alignment load-locks. Also disclosed is a method of patterning a wafer within a lithography system. The method can include a first step of placing the wafer on supports within an alignment load-lock. In a next step, the wafer is aligned with respect to a chuck while the wafer is supported within the alignment load-lock on the supports. In another step, the wafer is secured to the chuck.