A structure for a multi-level interconnect inter-level dielectric layer
(ILD), a method of manufacturing thereof, and a semiconductor device
including the ILD layer. The ILD layer includes a first low-dielectric
constant material sub-layer, and a second low-dielectric constant
material sub-layer disposed over the first low-dielectric constant
material sub-layer. The second low-dielectric constant material sub-layer
has at least one different material property than the first
low-dielectric constant material sub-layer. A third low-dielectric
constant material sub-layer is disposed over the second low-dielectric
constant material sub-layer, the third low-dielectric constant material
sub-layer having at least one different material property than the second
low-dielectric constant material sub-layer. The first, second and third
low-dielectric constant materials sub-layers are preferably comprised of
the same material, deposited continuously in one or more deposition
chambers while the deposition conditions such as the gas flow rate,
power, or gas species are adjusted or changed.