US Patent 9865567 Heterogeneous integration of integrated circuit device and companion device

An example method of manufacturing a semiconductor assembly includes: forming first integrated circuit (IC) dies and dummy dies; forming an interposer wafer including a top side having first mounting sites for the first IC dies and second mounting sites for second IC dies; attaching the first IC dies to the interposer wafer at the first mounting sites and the dummy dies to the interposer wafer at the second mounting sites; processing a backside and the top side of the interposer wafer; removing the dummy dies from the top side of the interposer wafer to expose the second mounting sites; and attaching the second IC dies to the interposer wafer at the exposed second mounting sites.