1X deep-UV lithography with chemical amplification for 1-micron DRAM production

Abstract

This paper describes methods used and results obtained in the production of 1-megabit (Mb) DRAM chips, using a chemically amplified tertiary-butoxy carhonyl hydroxystyrene (t-BOC) resist and 1X lithography. 'Flie internally developed resist provided high sensitivity and contrast, for I rn resolution on a Perkin Elmer Micralign model 500 (PE 500) in the deep UV. Characterization, and modification of the PE 500 were required for this first application in the deep UV. The manufacturing process had photo limited yield in excess of 95% with throughput of 100 wafers per hour.