Speci﬿c contact resistance of phase change materials to metal electrode

For phase change random access memory (PCRAM) cells, it is important to know the contact resistance of phase change materials (PCMs) to metal electrodes at the contacts. In this letter, we report the systematic determination of the speci﬿c contact resistance (Ͽc ) of doped Sb2Te and Ge2Sb2Te5 to TiW metal electrodes. These data are reported for both the amorphous and the crystalline states of these PCMs. The temperature and voltage dependences of Ͽc are also studied. A detailed understanding of these contacts is essential for the scaling, design, device modeling, and optimization of PCRAM cells