Hsinyu Tsai, Stefano Ambrogio, et al.
VLSI Technology 2019
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.
Hsinyu Tsai, Stefano Ambrogio, et al.
VLSI Technology 2019
J. M. Papalia, Nathan Marchack, et al.
SPIE Advanced Lithography 2016
S. G. Walton, D. R. Boris, et al.
JVSTA
Hsinyu Tsai, Hiroyuki Miyazoe, et al.
SPIE Advanced Lithography 2015