Impact of coma on CD control for multiphase PSM designs

Regina T. Schmidt; Chris A. Spence; Luigi Capodieci; Zoran Krivokapic; Bernd Geh; Donis G. Flagello

doi:10.1117/12.310750

29 June 1998 Impact of coma on CD control for multiphase PSM designs

Regina T. Schmidt, Chris A. Spence, Luigi Capodieci, Zoran Krivokapic, Bernd Geh, Donis G. Flagello

Proceedings Volume 3334, Optical Microlithography XI; (1998) https://doi.org/10.1117/12.310750
Event: 23rd Annual International Symposium on Microlithography, 1998, Santa Clara, CA, United States

Abstract

Alternating PSM applied selectively to transistor regions on the poly gate mask is one way to achieve smaller gate CDs and tighter CD control. When using multiphase PSMs we have observed, experimentally, a difference between the CDs of isolated lines when the phase shifter is on the right side compared to the left side (we have called this effect the PSM right-left effect). The effect is shown to correlate with lens coma and the magnitude of the effect is also a strong function of defocus. In this paper we present experimental data showing the magnitude of the effect and how it can be minimized by choosing optimum values of numerical aperture (NA) and partial coherence ((sigma) ). The magnitude of the effect within the stepper field is shown to correlate with measured coma values. The sensitivity of the effect to defocus was calculated. Aerial Image simulation was performed and found to predict the experimental behavior to within a factor of two. Variations in PSM design were explored using simulation. In general, the effect is reduced if the PSM layout is symmetrical. By comparing the sensitivity to coma of various PSM designs with the sensitivity of line pair structures on binary masks we were able to determine which designs had acceptable coma sensitivity.

Citation Download Citation

Regina T. Schmidt, Chris A. Spence, Luigi Capodieci, Zoran Krivokapic, Bernd Geh, and Donis G. Flagello "Impact of coma on CD control for multiphase PSM designs", Proc. SPIE 3334, Optical Microlithography XI, (29 June 1998); https://doi.org/10.1117/12.310750

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