| AVS 55th International Symposium & Exhibition | |
| Thin Film | Thursday Sessions |
| Session TF-ThM |
| Session: | Evaporation, Pulsed Laser Deposition, and Molecular Beam Epitaxy |
| Presenter: | S.W. Ryu, Seoul National University, South Korea |
| Authors: | S.W. Ryu, Seoul National University, South Korea J.H. Lee, Seoul National University, South Korea Y.B. Ahn, Seoul National University, South Korea C.S. Hwang, Seoul National University, South Korea H.J. Kim, Seoul National University, South Korea |
| Correspondent: | Click to Email |
Phase change random access memory (PCRAM) has attracted a great interest because it satisfies various demands for nonvolatile memory devices.1-3 PCRAM uses the reversible phase change between the crystalline and amorphous states of chalcogenide materials, such as Ge2Sb2Te5 (GST), brought about by Joule heating. However, the high level of Ires has been the major obstacle to the further scaling of PCRAM because of the limited on-current drive capability of the cell transistor (<0.5 mA/µmm). There have been several reports on the improvement of the switching performance of GST achieved by doping it with various impurities, such as N,4 O,5 Si,6 or SiO2.7 In the case of SiO2 doped GST (S-GST), it was reported that the reset current is reduced by approximately 50% compared to that of undoped GST. 12 The improvement in the phase change characteristics of GST films was investigated by doping the GST films with SiO2 using cosputtering at room temperature. As the sputtering power of SiO2 increased from 0 to 150 W, the activation energy for crystallization increased from 2.1±0.2 to 3.1±0.15 eV. SiO2 inhibited the crystallization of the amorphous GST films, which improved the long term stability of the amorphous phase. The melting point decreased with increasing concentration of SiO2,which reduced the power consumption as well as the reset current.
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