A multi-stacked package-on-package structure includes a method. The method includes: adhering a first die and a plurality of second dies to a substrate, the first die having a different function from each of the plurality of second dies; attaching a passive device over the first die; encapsulating the first die, the plurality of second dies, and the passive device; and forming a first redistribution structure over the passive device, the first die, and the plurality of second dies, the passive device connecting the first die to the first redistribution structure.