<title>Cost of ownership for soft x-ray projection lithography</title>

Abstract

ABSTRACTWe present a general analysis of cost of ownership for an integrated circuit production lithography system. We illustrate the method with examples from i-line and deep ultraviolet lithography, as well as soft-x-ray projection lithography. Tool utilization is emphasized as well as system throughput. Our analysis suggests that with 20 wafer per hour throughput, which may beattainable with soft-x-ray projection lithography, lithography costs will rise to four times today's i-line costs, or higher. In addition to throughput, reticles and photoresist will be cost drivers for this technology. 1. INTRODUCTIONSoft-x-ray projection lithography (SXPL) has generated considerable excitement in the integrated circuit (IC) communitybecause it has demonstrated sub-0. l-tm resolution with reduction Thus it holds forth the tantalizing possibility of ultra-large scale integrated circuit (ULSI) fabrication with resolution of that order. This is a task that cannot be accomplishedwith either i-line or deep ultraviolet (DUV) lithography.2 I-line technology is now firmly entrenched in IC manufacturing of 0.5-m critical dimension (CD) devices. DUV lithography is seen as the most likely usurper for the O.25-.tm CD device generation,yet it is not having an easy time gaining a foothold in manufacturing. The reasons for this are two: One is that the technology is