Abstract: Disclosed are semiconductor packages and methods of fabricating the same. The semiconductor package comprises a first redistribution substrate and a first semiconductor device on the first redistribution substrate. The first redistribution substrate includes a first dielectric layer that includes a first hole, an under-bump that includes a first bump part in the first hole and a second bump part that protrudes from the first bump part onto the first dielectric layer, an external connection terminal on a bottom surface of the first dielectric layer and connected to the under-bump through the first hole, a wetting layer between the external connection terminal and the under-bump, and a first barrier/seed layer between the under-bump and the first dielectric layer and between the under-bump and the wetting layer.