The function of upper-level interlayer dielectrics is to provide electrical isolation and structural integrity for the interconnect routing T2.Following the chemical mechanical polishing of the Ta-based liner and subsequent cleaning, a thin ILD 6-1 layer is typically deposited to seal the exposed interconnects against oxidation and contamination P2.ILD 6-2 is then deposited over ILD 6-1 to provide the necessary bulk thickness for the upcoming bond pad cavity photo and etch steps, building the re