After the formation and patterning of the aluminum bondpad and its associated Ta-based barrier layer, the exposed metal structures and trenches must be electrically isolated and mechanically protected A1.The ILD 6-3 deposition step serves as the foundational dielectric layer within the composite ILD6 stack, covering the newly etched metal features A2.In the context of a 40nm BSI CMOS Image Sensor, this layer must provide robust inter-metal dielectric (IMD) isolation to prevent parasitic capaciti