The use of in situ spectroscopic ellipsometry (SE) is demonstrated as a technique for studying photoresist dissolution. Experiments carried out using a J.A.Woollam M-2000 ellipsometer and a custom built cell designed for in situ film measurements show that bulk dissolution rate measurements using the SE technique agree with dissolution rate data obtained using multiwavelength interferometry. SE is also demonstrated as a method for measuring thin film dissolution rates, water sorption, and films that swell. An additional focus of this work was the topic of interfacial “gel” layer formation during photoresist dissolution. Ellipsometry and interferometry were used to test several photoresist resins, with an emphasis on phenolic polymers. Single and multiple layer models were used to analyze the data, and were compared to model calculations predicting formation of a gel layer. For the materials studied, interfacial gel layer formation in low molecular weight phenolic polymers was not detected, within the resolution of the experimental techniques (< 15 nm).

Date Published: 12 June 2003
PDF: 13 pages
Proc. SPIE 5039, Advances in Resist Technology and Processing XX, (12 June 2003); doi: 10.1117/12.485182

Published in SPIE Proceedings Vol. 5039:
Advances in Resist Technology and Processing XX
Theodore H. Fedynyshyn, Editor(s)