A semiconductor package includes a package substrate, a plurality of first semiconductor chips stacked on an upper surface of the package substrate in a stair-step configuration, the plurality of first semiconductor chips having an uppermost semiconductor chip at a first height from the upper surface of the package substrate, the uppermost semiconductor chip including a free end portion. Conductive wires respectively electrically connect chip pads of the first semiconductor chips to substrate pads of the package substrate. A plurality of first support structures each have a first end attached to the upper surface of the package substrate and an opposite second end attached to the free end portion of the uppermost semiconductor chip. The first support structures are inclined at an angle relative to the package substrate.