Premium
Plasma etching durability of poly(methyl methacrylate)
Author(s) -
Harada Katsuhiro
Publication year - 1981
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1981.070260620
Subject(s) - activation energy , etching (microfabrication) , materials science , arrhenius equation , plasma etching , permeation , decomposition , methyl methacrylate , dry etching , resist , arrhenius plot , polymer chemistry , reactive ion etching , chemical engineering , glass transition , layer (electronics) , composite material , analytical chemistry (journal) , polymer , polymerization , chemistry , organic chemistry , membrane , biochemistry , engineering
The decomposition of poly(methyl methacrylate) (PMMA), as a positive resist, in CF 4 /O 2 plasma etching has been studied in the thin film state in order to clarify the factors influencing the dry etching durability of resists. It becomes clear that the major PMMA decomposition in CF 4 /O 2 plasma etching proceeds by the mechanism of random chain scission because very small kinetic chain lengths are estimated from the gel permeation chromatography data. The Arrhenius plots for the plasma etching rate of PMMA bend above about the glass transition temperature ( T g ), where rapid increase of the etching rate and remarkable pattern deformation are observed. Activation energy of the PMMA etching rate which is changed by oxygen concentration and rf power indicates various values from 3.1 to 6.5 kcal/mol below about T g . The result of molecular weight variation in the cross section of the film suggests that the active species permeate into the film with fairly large speed and the PMMA decomposition occurs not only at the film surface but also at deep layer of the film.