Subquarter micron optical lithography with practical superresolution technique

Tohru Ogawa; Masaya Uematsu; Fumikatsu Uesawa; Mitsumori Kimura; Hideo Shimizu; Tatsuji Oda

doi:10.1117/12.209302

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26 May 1995 Subquarter micron optical lithography with practical superresolution technique

Tohru Ogawa, Masaya Uematsu, Fumikatsu Uesawa, Mitsumori Kimura, Hideo Shimizu, Tatsuji Oda

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Proceedings Volume 2440, Optical/Laser Microlithography VIII; (1995) https://doi.org/10.1117/12.209302
Event: SPIE's 1995 Symposium on Microlithography, 1995, Santa Clara, CA, United States

Abstract

Practical resolution, which is defined as the minimum geometry for a 1.0 micrometers depth of focus, in conventional krypton fluoride (KrF) excimer laser (248 nm) lithography is 0.30 micrometers . A new illumination technique, which uses a weak quadruple effect to enhance the depth of focus and to solve the current problems in the off-axis illumination techniques, has been developed. This new illumination technique is suitable for use with the attenuated phase shifting mask. With this combination technique, a 1.8 micrometers depth of focus using a 0.45 NA KrF excimer laser stepper can be achieved without a secondary peak in the distribution of light intensity for the various duties 0.30 micrometers space patterns. Even for hole patterns, a 2.0 micrometers common depth of focus can be achieved. These results indicate that KrF excimer laser lithography is a powerful candidate for beyond 0.25 micrometers -rule devices. It is also confirmed that i-line lithography is an expectable candidate for the second generation of 0.35 micrometers -rule devices.

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Tohru Ogawa, Masaya Uematsu, Fumikatsu Uesawa, Mitsumori Kimura, Hideo Shimizu, and Tatsuji Oda "Subquarter micron optical lithography with practical superresolution technique", Proc. SPIE 2440, Optical/Laser Microlithography VIII, (26 May 1995); https://doi.org/10.1117/12.209302

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