Metrology measurements for alignment of extreme ultraviolet lithography (EUVL) projection cameras can be optimized using the concept of misalignment modes. Using a metric called distance between subspaces, metrology measurements can be adjusted to increase sensitivity to a chosen camera- performance measure. For example, we have found that collecting exit-pupil wavefront measurements at locations outside the EUVL projection-camera's ring field of view can increase the sensitivity of such metrology measurements to chief-ray distortion. This paper describes the development of the University of Arizona Lithography Package (UALP), a software package that supports the types of computation, e.g., sensitivity-matrix calculation, and the types of analysis, e.g., singular value decomposition, that are required by the optimization of metrology measurements using misalignment modes. The description begins with a discussion of the ideas behind each step of the development process of UALP, including its use of ZEMAX. Along with the discussion of these steps, we describe the progression of our interface to ZEMAX. We describe the transition from the original ZEMAX extension model to the model using the Win32 library, and also our final version written using the Microsoft Foundation Class Library. We also introduce a diagnostic tool that was created to help a programmer interact with ZEMAX.
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