Semiconductor package

A semiconductor package, comprising:

• a semiconductor chip comprising a substrate comprising a front surface opposite to a rear surface, front pads on the front surface, through-electrodes electrically connected to the front pads, and rear pads on the through-electrodes, the through-electrodes penetrating the substrate and protruding to the rear surface;
• a step structure comprising a dummy substrate, a buffer layer on the dummy substrate, and a cavity penetrating the dummy substrate and the buffer layer, with the semiconductor chip in the cavity;
• and
• a dielectric layer on at least portions of the semiconductor chip and the step structure, and around the through-electrodes and the rear pads on the rear surface of the substrate,
• wherein the substrate and the dummy substrate comprise a first material, and
• wherein the buffer layer comprises a second material different from the first material.

A semiconductor package, comprising:

• a semiconductor chip comprising a substrate comprising a front surface opposite to a rear surface, front pads on the front surface, through-electrodes electrically connected to the front pads, and rear pads on the through-electrodes, the through-electrodes penetrating the substrate and protruding to the rear surface;
• a step structure around the semiconductor chip and comprising a lower surface opposite to an upper surface;
• a gap-fill dielectric layer on the rear surface of the semiconductor chip, and the upper surface of the step structure;
• a bonding dielectric layer on the gap-fill dielectric layer and on at least portions of the rear pads;
• and
• a top semiconductor chip on the semiconductor chip, and comprising connection pads in contact with the rear pads, and a bonding insulating layer on at least portions of the connection pads and in contact with the bonding dielectric layer,
• wherein an upper surface of the gap-fill dielectric layer and upper ends of the through-electrodes provide a flat surface with the bonding dielectric layer and the rear pads on the flat surface, and
• wherein the step structure comprises a buffer layer adjacent to the flat surface.