A. Matsuda et al., Influences of preparation conditions of sols on hardening behaviors of silica gel films for micro-patterning, J CERAM S J, 108(6), 2000, pp. 604-606
Changes in refractive index, thickness and structure of the poly (ethylene
glycol), (PEG), -containing silica gel films, prepared under various concen
trations of hydrochloric acid during the exposure to an ambient atmosphere
at room temperature, have been investigated to determine the influence of p
reparation conditions on the hardening behavior of the films in a patternin
g process, The PEG-containing silica gel films, derived from silica sols wh
ich were prepared under lower hydrochloric acid concentration, showed a ste
ep increase in refractive index and large shrinkage upon increasing the exp
osure time. The increase in refractive index and shrinkage of the films wer
e found to reflect the decrease of SI-OH groups and the development of Si-O
-Si network in the films, acceding to infrared absorption spectra, The proc
ess time to emboss micropatterns was shortened by using the gel films deriv
ed from silica sols which were prepared under a low hydrochloric acid conce
ntration. This result suggests that the silica gel film with a low degree o
f polymerization hardens rapidly.