A method of manufacturing a semiconductor package including forming a first semiconductor chip including a first substrate having a first and second surfaces and forming a second semiconductor chip including a second substrate having third and fourth surfaces. Arranging the second semiconductor chip on the first semiconductor chip such that bonding pads that are exposed from the front surface of the second semiconductor chip are bonded to conductive pads that are exposed from the rear surface of the first semiconductor chip. Forming a first through via having a first diameter and that penetrates the first substrate. Forming an insulating layer that exposes a first end of the first through via on the second surface of the first substrate, etching the first end of the first through via to a first depth, and applying a conductive material to the first end to form the conductive pad having a second diameter.