A semiconductor memory device includes an integrated circuit (IC) chip structure, wherein the IC chip includes a substrate, a memory cell disposed on the substrate, and a local well disposed on the substrate, wherein a conductivity type of the local well is different from a conductivity type of the substrate, a wiring stack structure disposed on the IC chip structure, wherein the wiring stack structure includes a signal transfer pattern connected to the memory cell through a signal interconnector, and a thermal dispersion pattern connected to the local well through a thermal interconnector, and a heat transfer structure connected to the thermal dispersion pattern for transferring heat to the thermal dispersion pattern from a heat source.