About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
Journal of Physics D: Applied Physics
Paper
Highly selective dry etching of polystyrene-poly(methyl methacrylate) block copolymer by gas pulsing carbon monoxide-based plasmas
Abstract
We propose a very selective PMMA removal method from poly(styrene-block-methyl methacrylate) (PS-b-PMMA) copolymer using gas pulsing cyclic etching. Flow ratio of hydrogen (H2) added to carbon monoxide (CO) plasma was periodically changed to control etch and deposition processes on PS. By controlling the process time of each etch and deposition step, full PMMA removal including etching of the neutral layer was demonstrated at 28 nm pitch, while PS thickness remained intact. This is more than 10 times higher etch selectivity than conventional continuous plasma etch processes using standard oxygen (O2), CO-H2 and CO-O2-based chemistries.