Challenges in excimer laser lithography for 256M DRAM and beyond

New chemically amplified positive resist and off-axis illumination technique of KrF excimer laser lithography has been developed and successfully applied to the fabrication of 0.25 mu m-rule 256M DRAM. For below 0.25 mu m pattern fabrication, ArF excimer laser lithography has been found to be very promising using newly developed chemically amplified ArF excimer laser positive resist and large field projection lens.<
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