Patent ID: 7394087

Claim:
A phase-changeable memory device comprising: a substrate having a contact region on an upper surface thereof; an insulating interlayer provided on the substrate, the insulating interlayer having an opening formed through the insulating interlayer, the opening exposing the contact region; a lower electrode provided in the opening of the insulating interlayer, the lower electrode having a nitrided surface portion and being in electrical contact with the contact region on the substrate, the nitrided surface portion of the lower electrode having an increased nitrogen concentration relative to a non-nitrided lower portion of the lower electrode; a phase-changeable material layer pattern provided on the lower electrode; and an upper electrode provided on the phase-changeable material layer pattern; wherein the insulating interlayer has a nitrided surface portion and the phase-changeable material layer is at least partially on the nitrided surface portion of the insulating interlayer, the nitrided surface portion of the insulating interlayer having an increased nitrogen concentration relative to a non-nitrided lower portion of the insulating interlayer.