Phase change memory based on Ge2Sb2Te5 capped between polygermanium layers

The effects of polygermanium interlayer, acting mainly as heating and thermal-resisting one, on performance of phase change memory are studied. Thermal simulation shows that the maximum temperature in Ge2Sb2Te5 layer is remarkably promoted when Ge2Sb2Te5 is capped between polygermanium layers. The maximum temperature location moves closer to the interface between Ge2Sb2Te5 and tungsten plug, significantly avoiding the parallel resistance in the reset state, which makes the memory more reliable. Electrical measurement shows that the polygermanium capped structure has a much lower reset current and larger resistance contrast compared to the one without polygermanium layers.

[1]  M. Wuttig,et al.  Phase-change materials for rewriteable data storage. , 2007, Nature materials.

[2]  Tow Chong Chong,et al.  Phase change random access memory cell with superlattice-like structure , 2006 .

[3]  Sung-Min Yoon,et al.  Polycrystalline silicon-germanium heating layer for phase-change memory applications , 2006 .

[4]  G. A. Slack,et al.  Thermal Conductivity of Silicon and Germanium from 3°K to the Melting Point , 1964 .

[5]  Florian Merget,et al.  Simulation-based comparison of cell design concepts for phase change random access memory. , 2007, Journal of nanoscience and nanotechnology.

[6]  Matthias Wuttig,et al.  Phase change materials: From material science to novel storage devices , 2007 .

[7]  Dae-Hwan Kang,et al.  An experimental investigation on the switching reliability of a phase change memory device with an oxidized TiN electrode , 2006 .

[8]  Bomy Chen,et al.  High Speed Chalcogenide Random Access Memory Based on Si2Sb2Te5 , 2007 .

[9]  Kuan-Neng Chen,et al.  Irreversible modification of Ge2Sb2Te5 phase change material by nanometer-thin Ti adhesion layers in a device-compatible stack , 2007 .

[10]  J. Cluzel,et al.  Thermal characterization and analysis of phase change random access memory , 2005 .

[11]  Songlin Feng,et al.  Advantages of SiSb phase-change material and its applications in phase-change memory , 2007 .

[12]  D. Ielmini,et al.  Anomalous Cells With Low Reset Resistance in Phase-Change-Memory Arrays , 2007, IEEE Electron Device Letters.