New applications of evanescent imaging for microlithography are introduced. The use of evanescent wave lithography (EWL) has been employed for 26nm resolution at 1.85NA using a 193nm ArF excimer laser wavelength to record images in a photoresist with a refractive index of 1.71. Additionally, a photomask enhancement effect is described using evanescent wave assist features (EWAF) to take advantage of the coupling of the evanescent energy bound at the substrate-absorber surface, enhancing the transmission of a mask opening through coupled interference.
Date of creation, presentation, or exhibit
Department, Program, or Center
Microelectronic Engineering (KGCOE)
Bruce W. Smith, Yongfa Fan, Jianming Zhou, Neal Lafferty, Andrew Estroff, "Evanescent wave imaging in optical lithography", Proc. SPIE 6154, Optical Microlithography XIX, 61540A (15 March 2006); doi: 10.1117/12.657322; https://doi.org/10.1117/12.657322
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