Effect of the partial coherence on reflective notching

Robert John Socha; Christopher J. Progler; Andrew R. Neureuther

doi:10.1117/12.275979

7 July 1997 Effect of the partial coherence on reflective notching

Robert John Socha, Christopher J. Progler, Andrew R. Neureuther

Proceedings Volume 3051, Optical Microlithography X; (1997) https://doi.org/10.1117/12.275979
Event: Microlithography '97, 1997, Santa Clara, CA, United States

Abstract

This paper explores through numerical simulation and experiment the role of partial coherent illumination on reflective notching in optical projection printing over a nonplanar substrate. The intensity in the photoresist when patterning a gate line over a LOCOS generated active area well covered in polysilicon was simulated with the rigorous electromagnetic simulation program TEMPEST-PCD which includes partial coherence through a decomposition method. The simulation results are compared to experimental SEM pictures of developed photoresist lines for patterning a gate over a trench with varying moat widths when using a DUV 248 nm stepper with a NA of 0.5 for a (sigma) of 0.3 and 0.6. Variations in linewidth of both plus and minus 20% are observed due to the interactions with the underlying topography. The simulations give physical insight into trends seen in the experimental critical dimension (CD) measurements. Simulations indicate that most of the effects observed are due to lateral specular reflection from the underlying structure aiding in the dissolution of the resist near the feature. These trends seen in simulation and in experiment indicate that the topography has a similar impact on the CD regardless of the coherence.

Citation Download Citation

Robert John Socha, Christopher J. Progler, and Andrew R. Neureuther "Effect of the partial coherence on reflective notching", Proc. SPIE 3051, Optical Microlithography X, (7 July 1997); https://doi.org/10.1117/12.275979

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