Abstract: ed resolution in optical imaging is desirable for a number of important applications, including advanced integrated circuit development. In sub-micrometer optical lithography, the wavelength of the exposing radiation is a main determinant of pattern resolution, given by the Rayleigh equation R $EQ k$-1$/ $DOT lambda/NA. There is an upper limit on lens numerical aperture imposed by optical design criteria; k-factors are also restricted by the physical limits of photosensitive material chemistry and practical limits of production processes; reducing the exposing wavelength is left as a logical pathway for achieving increased pattern resolution. This paper presents a novel imaging system for the use of 248 nm and 193 nm lithography. The system is designed to characterize resist materials used in advanced memory (64 Mb, 256 Mb) and high density bipolar IC manufacturing. The imaging system and its optics will be described along with process conditions used to pattern deep-UV sensitive photoresists. SEM photos of imaged wafers will be presented, and methods to further improve deep-UV pattern resolution will be discussed.!17
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