Integrated fan-out packages and methods of forming the same

A method comprising:

• forming a device package, wherein forming the device package comprises:
• forming a metallization pattern on a first surface of a composite layer, wherein the composite layer comprises a composite material and wherein the first surface is pitted;
• forming a first dielectric layer over the composite layer and the metallization pattern;
• forming a conductive pillar over the first dielectric layer and electrically connected to the metallization pattern;
• placing a first semiconductor device on the first dielectric layer, wherein the first semiconductor device is adjacent to and separated from the conductive pillar;
• encapsulating the first semiconductor device and the conductive pillar with an encapsulant;
• and
• forming a redistribution structure over the encapsulant;
• forming openings in a second surface of the composite layer to expose the metallization pattern;
• and
• attaching a top package to the device package using conductive connectors, wherein the conductive connectors extend through the openings in the composite layer.

A semiconductor package comprising:

• a lower package comprising:
• a die on a redistribution structure, the die electrically connected to the redistribution structure;
• a through via proximate the die and electrically connected to the redistribution structure;
• a molding material over the redistribution structure, the molding material extending from the die to the through via;
• and
• a composite layer over the die and the through via, the composite layer over a side of the die opposite the redistribution structure, wherein the composite layer comprises filler particles, wherein top surfaces and bottom surfaces of the composite layer are pitted;
• and
• a top package comprising external connections, wherein the external connections are connected to the lower package through openings in the composite layer.