Paper
26 March 2007 New projection optics and aberration control system for the 45-nm node
Toshiyuki Yoshihara, Bunsuke Takeshita, Atsushi Shigenobu, Yasuo Hasegawa, Yoshinori Ohsaki, Kazuhiko Mishima, Seiya Miura
Author Affiliations +
Abstract
The 65nm and the subsequent 45nm node lithography require very stringent CD control. To realize high-accuracy CD control on an exposure tool, it is essential to reduce wavefront aberrations induced by projection optics design and manufacturing errors and then stabilize the aberrations while the exposure tool is in operation. We have developed two types of new hyper-NA ArF projection optics to integrate into our new platform exposure tool: a dry system and a catadioptric system for immersion application. In this paper, aberration measurement results of these projection systems are shown, demonstrating that ultra-low aberration is realized. In addition, a new projection optical system has been developed which incorporates high degree-of-freedom Aberration Controllers and automatic aberration measuring sensors. These controllers and sensors are linked together through Aberration Solver, a software program to determine optimal target values for aberration correction, thereby allowing the projection optics to maintain its best optical properties. The system offers excellent performance in correcting aberrations that come from lens heating, and makes it possible to guarantee extremely low aberrations during operation of the exposure tool.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Toshiyuki Yoshihara, Bunsuke Takeshita, Atsushi Shigenobu, Yasuo Hasegawa, Yoshinori Ohsaki, Kazuhiko Mishima, and Seiya Miura "New projection optics and aberration control system for the 45-nm node", Proc. SPIE 6520, Optical Microlithography XX, 652022 (26 March 2007); https://doi.org/10.1117/12.711375
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CITATIONS
Cited by 4 scholarly publications.
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KEYWORDS
Projection systems

Monochromatic aberrations

Wavefront aberrations

Control systems

Sensors

Aberration correction

Optics manufacturing

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