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Drechsler, A. ; Bellmann, C. ; Synytska, A. ; Petong, N. ; Grundke, K. ; Stamm, M. ; Wunnicke, O.
Study of the Adsorption of a Cationic Surfactant on Photoresist Surfaces

PMSE 421 - The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006

A defect drastically reducing the yield in microelectronics manufacturing is the collapse of high aspect ratio photoresist patterns during drying in the photolithographic process. Tests in the production line showed that the pattern collapse can be reduced by rinsing the patterns with a solution of a cationic surfactant before drying. The present study investigates the adsorption of the cationic surfactant on photoresist surfaces with various methods. It is shown that cationic surfactants adsorb both on unexposed and exposed photoresist. On exposed resist which is more hydrophilic and more negatively charged than unexposed resist, a dense monolayer is formed due to electrostatic interactions which hydrophobizes the photoresist surface. A maximum of the receding contact angle of the surfactant solution is reached which correlates with maximum pattern collapse reduction. This explains the positive effect of the cationic surfactant rinse on the pattern collapse.

Polymeric Materials: Science and Engineering 51



August 2006


Nanostructured Materials