Optics and Optical Design - Microlithography Reduction Projection Stepper Lens Design: A Patent Study

I worked through a stepper lens patent application, and here is what I learned. A little bit about the lens. A little bit about microlithography. "Microlithography Reduction Projection Stepper." That's a lot of words modifying the one little word "lens". I just threw them all in there:) Optical Design Playlist: https://www.youtube.com/playlist?list=PLmfHzApbF5dbx_S_h9A13uLm4LVK0f6XK Please consider clicking on "LIKE". I don't get paid for creating this content, and your positive feedback is the only encouragement that I receive to continue creating this kind of helpful material. The document I examined was Japanese patent application 10-290584, “Projection optical system, exposure apparatus equipped with the same, and device manufacturing method”, Oct. 13, 1998. Reference that I consulted to help me make sense of it all were: 1. Matsuyama, Tomoyuki, Yasuhiro Ohmura, and David M. Williamson. "The lithographic lens: its history and evolution," Optical Microlithography XIX. Vol. 6154. SPIE, 2006. 2. Etka Sharma, Reena Rathi, Jaya Misharwal, Bhavya Sinhmar, Suman Kumari, Jasvir Dalal, and Anand Kumar. "Evolution in Lithography Techniques: Microlithography to Nanolithography," Nanomaterials 12, no. 16 (2022): 2754. 3. Joseph Braat and Peter Török. Imaging optics, Chapter 7, Cambridge University Press, 2019. 4. José Sasián, Introduction to lens design, p.36, Cambridge University Press, 2019. 5. Keith J. Kasunic, Optomechanical Systems Engineering, Chapter 9, Wiley, 2015. Image credits are: 1. Bdieseldorff, CC0, via Wikimedia Commons https://commons.wikimedia.org/wiki/File:Stepper.gif 2. Tom.vettenburg - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=29386487 #lensdesign #opticaldesign