Highly porous, low-k dielectric materials are mechanically reinforced to enable
the use of these low-k materials as interlayer dielectrics in advanced integrated
circuits such as those which incorporate highly porous ILD materials in a Cu damascene
interconnect technology. An integrated circuit, embodying such a mechanically reinforced
ILD generally includes a substrate having interconnected electrical elements therein,
a first dielectric layer disposed over the substrate, a plurality of electrically
insulating structures disposed on the first dielectric layer, and a second dielectric
layer disposed on the first dielectric layer such that the second dielectric surrounds
the plurality of structures. A process, for making a mechanically reinforced, highly
porous, low-k ILD, generally includes forming a first dielectric layer on a substrate,
patterning the first dielectric layer such that a plurality of structures are formed,
the structures each having a top surface, forming a second dielectric layer over
and adjacent to the structures, the second dielectric layer having a top surface,
and polishing the second dielectric layer such that its top surface is substantially
even with the top surfaces of the structures. The structures may be rectangular
posts, or more geometrically complex forms. The structures may be identical, or
a combination of various forms.