Processes for forming porous low k dielectric materials from low k
dielectric films containing a porogen material include exposing the low k
dielectric film to ultraviolet radiation. In one embodiment, the film is
exposed to broadband ultraviolet radiation of less than 240 nm for a
period of time and intensity effective to remove the porogen material. In
other embodiments, the low k dielectric film is exposed to a first
ultraviolet radiation pattern effective to increase a crosslinking
density of the film matrix while maintaining a concentration of the
porogen material substantially the same before and after exposure to the
first ultraviolet radiation pattern. The low k dielectric film can be
then be processed to form a metal interconnect structure therein and
subsequently exposed to a second ultraviolet radiation pattern effective
to remove the porogen material from the low k dielectrics film and form a
porous low k dielectric film.