Chemically amplified photoresists require a post exposure bake (PEB) to induce deprotection using a UV generated acid-catalyst. While reaction pathways for deprotection have been proposed, key challenges remain in modeling the reaction kinetics. In this work, we used a scanning line-focused laser beam as an alternate PEB method, to quantify the deprotection reaction kinetics of an ESCAP-type and a 193 nm model resist system at high temperatures in millisecond time frames. Results were compared with conventional PEB at 115°C for seconds time frames. Results show that the deprotection kinetics follow simple first-order reaction models only under laser PEB conditions, with more complex kinetics observed under hot plate PEB. FT-IR and NMR spectroscopies were used to characterize the reaction byproducts. Results suggest potential differences in deprotection mechanisms between the two PEB temperature and time regimes. The deprotection behavior obtained using this l-PEB technique enables a deeper understanding of the reaction kinetics of photoresists, critical for current DUV and future EUV technologies.

Date Published: 19 March 2012
PDF: 7 pages
Proc. SPIE 8325, Advances in Resist Materials and Processing Technology XXIX, 83250N (19 March 2012); doi: 10.1117/12.916605

Published in SPIE Proceedings Vol. 8325:
Advances in Resist Materials and Processing Technology XXIX
Mark H. Somervell; Thomas I. Wallow, Editor(s)