Focus improvement with NIR absorbing underlayer attenuating substructure reflectivity

Wu-Song Huang; Dario Goldfarb; Wai-kin Li; Martin Glodde; Kazumi Noda; Seiichiro Tachibana; Masaki Ohashi; Dah-Chung Owe-Yang; Takeshi Kinsho

doi:10.1117/12.916240

20 March 2012 Focus improvement with NIR absorbing underlayer attenuating substructure reflectivity

Wu-Song Huang, Dario Goldfarb, Wai-kin Li, Martin Glodde, Kazumi Noda, Seiichiro Tachibana, Masaki Ohashi, Dah-Chung Owe-Yang, Takeshi Kinsho

Author Affiliations +

Proceedings Volume 8325, Advances in Resist Materials and Processing Technology XXIX; 83251A (2012) https://doi.org/10.1117/12.916240
Event: SPIE Advanced Lithography, 2012, San Jose, California, United States

Abstract

Process dependent focus leveling errors occur in photolithography when there is unpredicted reflectivity originating from multilayer structures on the fully integrated process wafer. The typical wavelength used in optical focus sensors is in the near infrared (NIR) range which is highly transparent to most dielectric materials. Consequently, the reflected light from underlying structures perturbs the accuracy of the leveling signal reflected from resist surface. To alleviate this issue, air-gauge focus sensors have been used to measure the wafer surface topography for an in-situ calibration to correct the focus leveling error. Using an air-gauge sensor is a slow process and a throughput detractor. Therefore, an NIR-absorbing underlayer has been developed for easy insertion into existing resist coating processes. It has been demonstrated that the air-gauge sensor can be turned off without showing any degradation in leveling data or litho performance on back end of line (BEOL) integrated wafers.

Citation Download Citation

Wu-Song Huang, Dario Goldfarb, Wai-kin Li, Martin Glodde, Kazumi Noda, Seiichiro Tachibana, Masaki Ohashi, Dah-Chung Owe-Yang, and Takeshi Kinsho "Focus improvement with NIR absorbing underlayer attenuating substructure reflectivity", Proc. SPIE 8325, Advances in Resist Materials and Processing Technology XXIX, 83251A (20 March 2012); https://doi.org/10.1117/12.916240

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