Impact of illumination on model-based SRAF placement for contact patterning

John L. Sturtevant; Srividya Jayaram; Omar El-Sewefy; Aasutosh Dave; Pat LaCour

doi:10.1117/12.846620

3 March 2010 Impact of illumination on model-based SRAF placement for contact patterning

John L. Sturtevant, Srividya Jayaram, Omar El-Sewefy, Aasutosh Dave, Pat LaCour

Proceedings Volume 7640, Optical Microlithography XXIII; 764036 (2010) https://doi.org/10.1117/12.846620
Event: SPIE Advanced Lithography, 2010, San Jose, California, United States

Abstract

Sub-Resolution Assist Features (SRAFs) have been used extensively to improve the process latitude for isolated and semi-isolated features in conjunction with off-axis illumination. These SRAFs have typically been inserted based upon rules which assign a global SRAF size and proximity to target shapes. Additional rules govern the relationship of assist features to one another, and for random logic contact layers, the overall ruleset can become rather complex. It has been shown that model-based placement of SRAFs for contact layers can result in better worst-case process window than that obtained with rules, and various approaches have been applied to affect such placement. The model comprehends the specific illumination being used, and places assist features according to that model in the optimum location for each contact hole. This paper examines the impact of various illumination schemes on model-based SRAF placement, and compares the resulting process windows. Both standard illumination schemes and more elaborate pixel-based illumination pupil fills are considered.

Citation Download Citation

John L. Sturtevant, Srividya Jayaram, Omar El-Sewefy, Aasutosh Dave, and Pat LaCour "Impact of illumination on model-based SRAF placement for contact patterning", Proc. SPIE 7640, Optical Microlithography XXIII, 764036 (3 March 2010); https://doi.org/10.1117/12.846620

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