A semiconductor device including an integrated circuit, a plurality of conductive pillars, and a protection layer is provided. The integrated circuit includes a semiconductor substrate and an interconnection structure covering the semiconductor substrate, wherein the interconnection structure includes a plurality of patterned conductive layers and a plurality of inter-dielectric layers stacked alternately, the topmost patterned conductive layer of the patterned conductive layers is covered by the topmost inter-dielectric layer of the inter-dielectric layers, and the topmost patterned conductive layer is exposed by a plurality of openings of the topmost inter-dielectric layer. The conductive pillars are disposed on the topmost patterned conductive layer exposed by the openings, and the conductive pillars are electrically connected to the topmost patterned conductive layer through the openings. The protection layer covers the integrated circuit and the conductive pillars. A method for fabricating the semiconductor device and a method for fabricating integrated fan-out packages including the semiconductor device are also provided.