Interconnected Wafer Stack

Both micrographs show a cross-section of a three-wafer stack connected with copper Super-Vias. In both photos, the bottom wafer is face up, with silicon on the bottom and copper bondpoints on the top; the upper two wafers are face down (silicon on the top).

Interconnected Wafer Stack

Picture 1 of 2

June, 2003 Three Super-Via™ connections are visible here - the leftmost connection pierces the top two wafers; the middle connection pierces all three wafers; the rightmost connection pierces only the bottom wafer.