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