Micro-optics: enabling technology for illumination shaping in optical lithography

Reinhard Voelkel

doi:10.1117/12.2046116

31 March 2014 Micro-optics: enabling technology for illumination shaping in optical lithography

Reinhard Voelkel

Proceedings Volume 9052, Optical Microlithography XXVII; 90521U (2014) https://doi.org/10.1117/12.2046116
Event: SPIE Advanced Lithography, 2014, San Jose, California, United States

Abstract

Optical lithography has been the engine that has empowered semiconductor industry to continually reduce the half-pitch for over 50 years. In early mask aligners a simple movie lamp was enough to illuminate the photomask. Illumination started to play a more decisive role when proximity mask aligners appeared in the mid-1970s. Off-axis illumination was introduced to reduce diffraction effects. For early projection lithography systems (wafer steppers), the only challenge was to collect the light efficiently to ensure short exposure time. When projection optics reached highest level of perfection, further improvement was achieved by optimizing illumination. Shaping the illumination light, also referred as pupil shaping, allows the optical path from reticle to wafer to be optimized and thus has a major impact on aberrations and diffraction effects. Highly-efficient micro-optical components are perfectly suited for this task. Micro-optics for illumination evolved from simple flat-top (fly’s-eye) to annular, dipole, quadrupole, multipole and freeform illumination. Today, programmable micro-mirror arrays allow illumination to be changed on the fly. The impact of refractive, diffractive and reflective microoptics for photolithography will be discussed.

Citation Download Citation

Reinhard Voelkel "Micro-optics: enabling technology for illumination shaping in optical lithography", Proc. SPIE 9052, Optical Microlithography XXVII, 90521U (31 March 2014); https://doi.org/10.1117/12.2046116

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