A semiconductor package includes a first semiconductor chip stacked on a package substrate in which a first surface of the first semiconductor chip faces the package substrate and a second surface that is opposite to the first surface, a second semiconductor chip stacked on the first semiconductor chip that includes a third surface facing the first semiconductor chip and a fourth surface that is opposite to the third surface, and an integral adhesive structure that substantially continuously fills a first space between the package substrate and the first semiconductor chip and a second space between the first and second semiconductor chips. The integral adhesive structure includes an extension protruding from outer sidewalls of the first and second semiconductor chips. The extension has one continuously convex sidewall between a level of the first surface and a level of the fourth surface.