Dv. Nicolau et C. Bercu, Monitoring photoresist glass transition temperature versus processing parameters via NMR broad band spectroscopy, MICROELEC J, 31(8), 2000, pp. 677-683
We propose a method for the monitoring of the glass transition temperature
of the resists used in semiconductor lithography based on the broad-band nu
clear magnetic resonance technique. The method is capable to trace the evol
ution of the mobility of several major chemical species present in a resist
system versus processing parameters, e.g. exposure energy and bake tempera
ture. The most important components, namely the lower molecular weight phot
oactive compound and the higher molecular weight base resin, were character
ized, in accordance with their characteristic signals, as mobile and the ri
gid component, respectively. The method has the potential for being used fo
r process optimization and for on-line monitoring. (C) 2000 Elsevier Scienc
e Ltd. All rights reserved.