1 January 1987 Intelligent Optical System Of A New Stepper
Author Affiliations +
Optical steppers have opened their new era beyond 1 Am barrier. In order to achieve submicron lithography, however, steppers have been obliged to solve many problems that were not noticed before. For example, reduction lenses that were recognized as stable components have now become dynamic and intelligent system. There are three basic parameters in the projection optics---- resolution, depth of focus and distortion. As for resolution, the uniformity of the image quality over the whole field is required. The SEM image of 0.8 Am and its uniformity are discussed and some simulation results are shown. Depth of focus is the second point and is recognized as one of the most critical parameters in optical lithography. In order to achieve large depth of focus, new optical auto-focus system is introduced. This system has two features. One is the grazing angle of incidence and the other is the multiple wavelength effect. The third point is distortion, which is the final key for overlay accuracy. The stability of distortion due. to barometric compensation and the machine to machine mixture problems will be discussed in detail.
© (1987) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Akiyoshi Suzuki, Shuuichi Yabu, Masami Ookubo, "Intelligent Optical System Of A New Stepper", Proc. SPIE 0772, Optical Microlithography VI, (1 January 1987); doi: 10.1117/12.967034; https://doi.org/10.1117/12.967034


Practical I-Line Lithography
Proceedings of SPIE (August 20 1986)
Practical Considerations Of Submicron Photolithography
Proceedings of SPIE (January 01 1987)
Advances In 1:1 Optical Lithography
Proceedings of SPIE (January 01 1987)
Deep-UV diagnostics using continuous tone photoresist
Proceedings of SPIE (July 01 1991)
New I-Line Lenses For Submicron Lithography
Proceedings of SPIE (January 01 1987)

Back to Top