PROSPECTS FOR X-RAY-LITHOGRAPHY

The essentials of proximity x-ray lithography (XRL) have been established and successful alternative implementations have been demonstrated in academic and industrial laboratories worldwide. Results continue to show that XRL can provide simpler and more robust processes than optical or electron beam alternatives. And it is widely accepted that this becomes more true as lithographic dimensions shrink. So why do we still await the introduction of the first commercial use of XRL? Use of a new technology requires its either attaining the unattainable or excelling at cost/performance. For near term application, XRL must leap the latter hurdle. While most concede the superior robustness of XRL to normal process variation, popular lore has it that availability or an adequate infrastructure limits XRL becoming a process of choice. We discuss the current state of XRL against this competitive challenge and project progress forward. In so doing, we find that XRL is now approaching a critical crossroad. While optical approaches struggle to demonstrate technical realization and electron beam approaches are losing ground in the pixel per chip per second race, XRL's challenge is to mature its infrastructure sufficiently to attract proponents eager to make it the process of choice. The pace of XRL efforts leads us to the conclusion that XRL can be the process of choice for 250 nm applications, most probably beginning with 256 Mb DRAM or NVRAM.