In the 40nm BSI CMOS Image Sensor process flow, the Direct Bond Interconnect (DBI) module requires highly precise top-level metal structures for subsequent hybrid bonding P2.The ILD 6-2 Etch step is a critical phase within a multi-step dual-damascene etching sequence, positioned between the initial mask opening (ILD 6-5 to 6-3) and the final barrier/etch-stop clearing (ILD 6-1) A1.Its primary function is to anisotropically remove the bulk interlayer dielectric material to form the interconnect t