Disclosed are semiconductor packages and their fabricating methods. The semiconductor package comprises a redistribution substrate, a semiconductor chip on a top surface of the redistribution substrate, and a solder terminal on a bottom surface of the redistribution substrate. The redistribution substrate includes an under-bump pattern in contact with the solder terminal, a dielectric layer on a sidewall of the under-bump pattern, an under-bump seed pattern between the dielectric layer and the sidewall of the under-bump pattern, and a redistribution pattern on the under-bump pattern. The under-bump pattern has central and edge regions. A first top surface at the edge region of the under-bump pattern is at a level higher than that of a second top surface at the central region of the under-bump pattern. An angle between the bottom surface and the sidewall of the under-bump pattern is in a range of 110° to 140°.