An interconnect structure is provided that includes a dielectric material
52' having a dielectric constant of 4.0 or less and including a plurality
of conductive features 56 embedded therein. The dielectric material 52'
has an upper surface 52r that is located beneath an upper surface of each
of the plurality of conductive features 56. A first dielectric cap 58 is
located on the upper surface of the dielectric material 52' and extends
onto at least a portion of the upper surface of each of the plurality of
conductive features 56. As shown, the first dielectric cap 58 forms an
interface 59 with each of the plurality of conductive features 56 that is
opposite to an electrical field that is generated by neighboring
conductive features. The inventive structure also includes a second
dielectric cap 60 located on an exposed portion of the upper surface of
each of the plurality of conductive features 56 not covered with the
first dielectric cap 58. The second dielectric cap 60 further covers on
an exposed surface of the first dielectric cap 58.