Photolithography overview for 64 megabit production

The joint IBM and Siemens 64 megabit development program has recently demonstrated successful fabrication of a 64 megabit prototype DRAM. Even with significant reduction in groundrules compared to the 16 Megabit DRAM, a photolithography process was developed and implemented with a high degree of success. This paper describes the tool set, the process and its performance and some of the issues faced in achieving this accomplishment. © 1994.