Highly selective dry etching of polystyrene-poly(methyl methacrylate) block copolymer by gas pulsing carbon monoxide-based plasmas. (21st April 2017)

• Record Type: Journal Article
• Authors: Miyazoe, Hiroyuki; Jagtiani, Ashish V; Tsai, Hsin-Yu; Engelmann, Sebastian U; Joseph, Eric A
• Is Part Of: Journal of physics. Volume 50:Number 20(2017)
• Publication Date: 2017-04-21
• Subjects: plasma etching -- gas pulsing -- directed self assembly -- atomic layer etch -- selective deposition -- block copolymer -- reactive ion etch; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/aa68c6
• Languages: English
• ISSNs: 0022-3727

Abstract

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.