Why do weak acids not work in 193-nm photoresists?: matrix effects on acid-catalyzed deprotection

Gerd Pohlers; George G. Barclay; Azher Razvi; Carolyne Stafford; Anthony Barbieri; James F. Cameron

doi:10.1117/12.537186

14 May 2004 Why do weak acids not work in 193-nm photoresists?: matrix effects on acid-catalyzed deprotection

Gerd Pohlers, George G. Barclay, Azher Razvi, Carolyne Stafford, Anthony Barbieri, James F. Cameron

Proceedings Volume 5376, Advances in Resist Technology and Processing XXI; (2004) https://doi.org/10.1117/12.537186
Event: Microlithography 2004, 2004, Santa Clara, California, United States

Abstract

The present report investigates the chemical/physical parameters that influence chemically amplified photoresist deprotection chemistry. It was observed that the efficiency of the acid catalyzed deprotection chemistry used in chemically amplified photoresists is highly dependent on chemical environment. In the first part, a solution IR spectroscopic investigation was conducted on the deprotection kinetics of a model probe molecule, t-butyl phenyl carbonate, in a variety of solvents. The solvent used in this study where chosen to mimic the chemical composition of typical photoresist polymers used KrF and ArF lithography. It was observed that the activation energy of the deprotection of the probe molecule was strongly dependent upon the polarity and chemical nature of the model solvent systems investigated. In the second part, the probe molecule approach was modified so it can be used to study deprotection kinetics in actual resist films. Therefore, a novel, in-situ technique for monitoring acid-catalyzed deprotection in real-time via absorption spectroscopy was developed. Coumarin 338, which exhibits a significant change in the absorption spectrum upon loss of its t-butyl group, was used as probe molecule. This new methodology offers a number of advantages over existing techniques. The results obtained with this method show a similar dependence of the deprotection kinetics on the polarity of the matrix as those in solution.

Citation Download Citation

Gerd Pohlers, George G. Barclay, Azher Razvi, Carolyne Stafford, Anthony Barbieri, and James F. Cameron "Why do weak acids not work in 193-nm photoresists?: matrix effects on acid-catalyzed deprotection", Proc. SPIE 5376, Advances in Resist Technology and Processing XXI, (14 May 2004); https://doi.org/10.1117/12.537186

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