Performance of the FPA-7000AS7 1.35 NA immersion exposure system for 45-nm mass production

True polarization characteristics of hyper-NA optics excluding impact of measurement system

“…In our case, because state-of-the-art projection lenses used in lithography have considerably large mass, we cannot circumvent the stress-induced birefringence completely in a gravity field because of the force acting on the lens supported mechanically. The third one ijmn (2) k m k n is the birefringence due to the translation symmetrical structure of crystals, which cannot be observed in visible wavelength.…”

“…As a result, anisotropy oriented to crystal axes occurs in an ArF laser even in a cubic crystal. This birefringence is called intrinsic birefringence, which is a product of fourth rank tensor ijmn (2) and second rank wave vector tensor k m k n .…”

Translational-symmetry alternating phase shifting mask grating mark used in a linear measurement model of lithographic projection lens aberrations

“…The extension of optical lithography life does not only owe to the application of resolution enhancement techniques (RET), high numerical aperture (NA), the double patterning technique, etc., but also to the continual decrease of the projection lens aberrations, which is an indispensable condition. A well-manufactured and assembled lithographic project lens can achieve ultralow aberrations with a total RMS of less than 5 mλ [2]. The aberrations are going to accumulate to deteriorate the image quality while the exposure time of lithographic tools becomes longer and longer [3].…”

“…Several in situ measurement techniques based on different measurement principles have been all available [2][3][4][5][6][7][8]. Based on the line diffraction interferometer principle, Canon has developed the in situ phase measurement interferometer (iPMI) technique [6], which is used on the 45 nm hp devices enabled lithographic tools FPA-7000AS7 and has a measurement repeatability of 2 mλ [2,5].…”

“…Based on the line diffraction interferometer principle, Canon has developed the in situ phase measurement interferometer (iPMI) technique [6], which is used on the 45 nm hp devices enabled lithographic tools FPA-7000AS7 and has a measurement repeatability of 2 mλ [2,5]. Based on the lateral shearing interferometer principle, ASML has developed the integrated lens interferometer at scanner 0003-6935/09/193654-10$15.00/0 © 2009 Optical Society of America (ILIAS) technique, and its repeatable accuracy achieves 2:5 mλ [7].…”