The saga of sigma: influences of illumination throughout optical generations

Bruce W. Smith

doi:10.1117/12.2048827

4 April 2014 The saga of sigma: influences of illumination throughout optical generations

Bruce W. Smith

Proceedings Volume 9052, Optical Microlithography XXVII; 905204 (2014) https://doi.org/10.1117/12.2048827
Event: SPIE Advanced Lithography, 2014, San Jose, California, United States

Abstract

The optimization of illumination in optical lithography has been central to the progress toward λ/5 resolution now commonplace. The tailoring of source shapes to meet increasing demands of imaging has been commercially practiced for over twenty years. The influence of illumination in microscopy and micrography had been explored for centuries before an adequate description was developed in the late nineteenth century. By the mid-twentieth century, the mathematical foundation for the dependency of resolution on illumination was presented, leading to the parameterization of illumination through a partial coherence factor (σ). The role of partial coherence in microscopy, micrography, and microlithography has been critical to the extension of resolution in each of these fields and has allowed for the application of optical lithography toward sub-50nm resolution. Today, source customization, polarized illumination, and source/mask domain co-optimization have become critical tools used to achieve manufacturable lithography resolution at the edge of physical limits. This paper will provide a historical look into how illumination, partial coherence, and source shaping has influenced optical lithography. Aspects relative to future lithography generations are also explored, including illumination influences with 3D effects especially important for EUV wavelength applications.

Citation Download Citation

Bruce W. Smith "The saga of sigma: influences of illumination throughout optical generations", Proc. SPIE 9052, Optical Microlithography XXVII, 905204 (4 April 2014); https://doi.org/10.1117/12.2048827

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available