Threshold field of phase change memory materials measured using phase change bridge devices

The threshold switching effect of phase change memory devices is typically parameterized by the threshold voltage at which this breakdown occurs. Using phase change memory bridge devices of variable length, we prove unambiguously that the important parameter for threshold switching is a critical electrical field and not a threshold voltage. By switching phase change bridge devices from the amorphous-as-deposited state, we obtain threshold fields for Ge15Sb85, Ag- and In-doped Sb2Te, Ge2Sb2Te5, and 4 nm thick Sb devices of 8.1, 19, 56, and 94 V/μm, respectively.

[1]  A. Pirovano,et al.  Electronic switching in phase-change memories , 2004, IEEE Transactions on Electron Devices.

[2]  M. Lankhorst,et al.  Low-cost and nanoscale non-volatile memory concept for future silicon chips , 2005, Nature materials.

[3]  A. Owen,et al.  Electronic conduction and switching in chalcogenide glasses , 1973 .

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

[5]  Daniele Ielmini,et al.  Analytical model for subthreshold conduction and threshold switching in chalcogenide-based memory devices , 2007 .

[6]  M. Stiddard.  Thin films of antimony on metallic substrates: crystallite orientation and critical thickness for the occurrence of the amorphous-crystalline phase transition , 1985 .

[7]  Kenkichi Tanioka,et al.  Lucky drift impact ionization in amorphous semiconductors , 2004 .

[8]  Brian K. Ridley,et al.  Soft-threshold lucky drift theory of impact ionisation in semiconductors , 1987 .

[9]  Electronic nature of amorphous threshold switching , 1975 .

[10]  D. Emin.  Current-driven threshold switching of a small polaron semiconductor to a metastable conductor , 2006 .

[11]  C. M. Jefferson,et al.  Characterization of phase change memory materials using phase change bridge devices , 2009 .

[12]  Sir Nevill Mott,et al.  The mechanism of threshold switching in amorphous alloys , 1978 .

[13]  Matthias Wuttig,et al.  SET Characteristics of Phase Change Bridge Devices , 2008 .

[14]  A. Pirovano,et al.  Threshold switching and phase transition numerical models for phase change memory simulations , 2008 .

[15]  S. Kasap,et al.  Lucky-drift model for impact ionization in amorphous semiconductors , 2009 .