Negative tone development: gaining insight through physical simulation

Stewart A. Robertson; Michael Reilly; John J. Biafore; Mark D. Smith; Young Bae

doi:10.1117/12.879506

15 April 2011 Negative tone development: gaining insight through physical simulation

Stewart A. Robertson, Michael Reilly, John J. Biafore, Mark D. Smith, Young Bae

Proceedings Volume 7972, Advances in Resist Materials and Processing Technology XXVIII; 79720Y (2011) https://doi.org/10.1117/12.879506
Event: SPIE Advanced Lithography, 2011, San Jose, California, United States

Abstract

A simple analysis of aerial image quality reveals that negative tone imaging is superior to positive tone for small dimension contacts and trenches. Negative Tone Development (NTD) of positive chemically amplified (de-protecting) photoresist is currently the favored method for realizing such images on the wafer. When experimental process windows are determined for NTD systems, it is apparent that the results far exceed the upper limit predicted using current physical modeling. Since real data transcends the capabilities of the current model to predict, some important physical process is clearly missing. In this work, we explore whether resist shrinkage during PEB can account for the observed discrepancies. Two very simple shrinkage models are developed and tested. Results show that shrinkage in the vertical direction explains some profile artifacts observed in actual NTD processes but has negligible impact on conventional positive tone processes. The horizontal shrinkage model reveals that this type of phenomenon can significantly increase the exposure latitude of a negative tone process but has marginal impact on positive tone exposure latitude only introducing a small CD offset. While horizontal shrinkage does enhance exposure latitude appreciably, the effect does not seem large enough on its own to account for the entire increase observed in the experimental results. Further work is ongoing to investigate other potential mechanisms for observed behavior.

Citation Download Citation

Stewart A. Robertson, Michael Reilly, John J. Biafore, Mark D. Smith, and Young Bae "Negative tone development: gaining insight through physical simulation", Proc. SPIE 7972, Advances in Resist Materials and Processing Technology XXVIII, 79720Y (15 April 2011); https://doi.org/10.1117/12.879506

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