Micro-Processing by ArF Excimer Laser

Abstract

KrF/ ArF excimer laser lithography technique are expected to realize 1-4 Gbit DRAMs below 0.25μm designrules. Although KrF lithography is extendable for less than 0.2 μm patterning, the introduction of ArF lithography is much simple solution, if the infrastructures of ArF lithography are available. To realize ArFlithography in mass production, the development of ArF resists, exposure tools, and masks are important.Regarding ArF resists, practical chemically amplified resist has been developed with alicyclic polymers. Thedevelopment of dry-developed processes using silylation techniques also improves the resolution. Thecombination of recent ArF resist, anti-reflecting coating and attenuating phase shifting mask can producedevice patterns with a 0.12 μm design rule. The use of TSI can produce 0.09μm Line & Space (L&S) patternswith Levenson phase shift mask. These results imply that ArF lithography can be used for multi-generation indevice manufacturing. ArF lithography will be introduced in mass production as post-KrF lithography in thenear future.