Translator Disclaimer
20 August 1986 Alignment Wavelength Optimization For Wafer Stepper Microscope
Author Affiliations +
In modern photolithography, alignment to targets which are burried under layers of highly absorptive coatings at the actinic wavelength, is a severe problem. A novel optical technique has been developed at TRE allowing the use of an arbitrary optical wavelength for target alignment. Significant improvement in target image quality and in system alignment accuracy has been achieved when the alignment wavelength is optimized for minimum process layer absorption and stepper lens aberration. In this paper, the optical approach which corrects for chromatic aberration and astigmatism of the stepper lens will be described. Technical data with a number of commonly used, highly absorptive materials will be presented. Better than 0.25 micron three sigma alignment in realistic absorptive process layers has been achieved with this technique.
© (1986) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Sungmuk Lee, Shi-kay Yao, and Michele Nuhn "Alignment Wavelength Optimization For Wafer Stepper Microscope", Proc. SPIE 0633, Optical Microlithography V, (20 August 1986);


Fractured Alignment Mark Technology For Wafer Steppers
Proceedings of SPIE (August 20 1986)
Comparison Of Autoalign Techniques
Proceedings of SPIE (September 13 1982)
Image-height offset in TTL on-axis alignment method
Proceedings of SPIE (June 01 1990)
Improvements in 0.5-micron production wafer steppers
Proceedings of SPIE (July 01 1991)
Detection of focus and spherical aberration by use of a...
Proceedings of SPIE (September 14 2001)
Dark Field Technology A Practical Approach To Local...
Proceedings of SPIE (January 01 1987)

Back to Top