Techniques of shallow trench isolation and devices produced therefrom
are shown. The techniques of shallow trench isolation utilize foamed polymers,
cured aerogels or air gaps as the insulation medium. Such techniques facilitate
lower dielectric constants than the standard silicon dioxide due to the cells of
gaseous components inherent in foamed polymers, cured aerogels or air gaps. Lower
dielectric constants reduce capacitive coupling concerns and thus permit higher
device density in an integrated circuit device. The shallow trench isolation structures
are used on a variety of substrates including silicon-on-insulator (SOI) substrates
and silicon-on-nothing (SON) substrates.