A semiconductor package including a substrate; a semiconductor stack on the substrate; an underfill between the substrate and the semiconductor stack; an insulating layer conformally covering surfaces of the semiconductor stack and the underfill; a chimney on the semiconductor stack; and a molding member surrounding side surfaces of the chimney, wherein the semiconductor stack has a first upper surface that is a first distance from the substrate and a second upper surface that is a second distance from the substrate, the first distance being greater than the second distance, wherein the chimney includes a thermally conductive filler on the first and second upper surfaces of the semiconductor stack, the thermally conductive filler having a flat upper surface; a thermally conductive spacer on the thermally conductive filler; and a protective layer on the thermally conductive spacer, and wherein an upper surface of the thermally conductive spacer is exposed.