3D Interconnects—Through Silicon Vias (TSVs)
Olympus FR3220IR Metrology Tool
Using an infrared (IR) microscope, near infrared (NIR) wavelengths (1310 nm) are used to "see" through silicon wafers to inspect and measure features as small as 0.5 microns at the interface of a bonded wafer pair. Features can be defects, or alignment fiducials that allow the characterization of overlay error between the top and bottom wafers of the bonded pair.
