This invention has enabled a new, simple nanoporous dielectric fabrication
method. In general, this invention uses a polyol, such as glycerol, as a
solvent. This new method allows both bulk and thin film aerogels to be
made without supercritical drying, freeze drying, or a surface
modification step before drying. Prior art aerogels have required at least
one of these steps to prevent substantial pore collapse during drying.
Thus, this invention allows production of nanoporous dielectrics at room
temperature and atmospheric pressure, without a separate surface
modification step. Although not required to prevent substantial
densification, this new method does not exclude the use of supercritical
drying or surface modification steps prior to drying. In general, this new
method is compatible with most prior art aerogel techniques. Although this
new method allows fabrication of aerogels without substantial pore
collapse during drying, there may be some permanent shrinkage during aging
and/or drying.
