A wafer-level packaged IC is made by attaching a cap wafer to the front of
an IC base wafer before cutting the IC base wafer, i.e. before
singulating the plurality of dies on the IC base wafer. The cap wafer is
mechanically attached and electrically connected to the IC base wafer,
then the dies are singulated. Electrically conductive paths extend
through the cap wafer, between wafer contact pads on the front surface of
the cap and electrical contact points on the IC base wafer. Optionally,
the cap wafer contains one or more dies. The IC base wafer can be
fabricated according to a different technology than the cap wafer,
thereby forming a hybrid wafer-level package. Optionally, additional
"upper-level" cap wafers (with or without dies) can be stacked to form a
"multi-story" IC. Optionally, a hermetically-sealed cavity headroom is
provided.