Contact resistance change memory using N-doped Cr2Ge2Te6 phase-change material showing non-bulk resistance change

Phase-change random access memory (PCRAM) is enabled by a large resistance contrast between amorphous and crystalline phases upon reversible switching between the two states. Thus, great efforts have been devoted to identifying potential phase-change materials (PCMs) with large electrical contrast to realize a more accurate reading operation. In contrast, although the truly dominant resistance in a scaled PCRAM cell is contact resistance, less attention has been paid toward the investigation of the contact property between PCMs and electrode metals. This study aims to propose a non-bulk-resistance-dominant PCRAM whose resistance is modulated only by contact. The contact-resistance-dominated PCM exploited here is N-doped Cr2Ge2Te6 (NCrGT), which exhibits almost no electrical resistivity difference between the two phases but exhibits a typical switching behavior involving a three-order-of-magnitude SET/RESET resistance ratio owing to its large contact resistance contrast. The conduction mechanism was discussed on the basis of current–voltage characteristics of the interface between the NCrGT and the W electrode.Phase-change random access memory (PCRAM) is enabled by a large resistance contrast between amorphous and crystalline phases upon reversible switching between the two states. Thus, great efforts have been devoted to identifying potential phase-change materials (PCMs) with large electrical contrast to realize a more accurate reading operation. In contrast, although the truly dominant resistance in a scaled PCRAM cell is contact resistance, less attention has been paid toward the investigation of the contact property between PCMs and electrode metals. This study aims to propose a non-bulk-resistance-dominant PCRAM whose resistance is modulated only by contact. The contact-resistance-dominated PCM exploited here is N-doped Cr2Ge2Te6 (NCrGT), which exhibits almost no electrical resistivity difference between the two phases but exhibits a typical switching behavior involving a three-order-of-magnitude SET/RESET resistance ratio owing to its large contact resistance contrast. The conduction mechanism was discus...

[1]  Deepu Roy,et al.  Specific Contact Resistance of Phase Change Materials to Metal Electrodes , 2010, IEEE Electron Device Letters.

[2]  H.-S. Philip Wong,et al.  Phase Change Memory , 2010, Proceedings of the IEEE.

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

[4]  D. Ielmini,et al.  Phase change materials and their application to nonvolatile memories. , 2010, Chemical reviews.

[5]  Effect of metals and annealing on specific contact resistivity of GeTe/metal contacts , 2012 .

[6]  A. Yu,et al.  Electron tunneling and contact resistance of metal-silicon contact barriers , 1970 .

[7]  Matthias Wuttig,et al.  Towards a universal memory? , 2005, Nature materials.

[8]  Ekmel Ozbay,et al.  Tunneling current via dislocations in Schottky diodes on AlInN/AlN/GaN heterostructures , 2009 .

[9]  Daisuke Ando,et al.  Inverse Resistance Change Cr2Ge2Te6-Based PCRAM Enabling Ultralow-Energy Amorphization. , 2018, ACS Applied Materials and Interfaces.

[10]  V. Weidenhof,et al.  Structural transformations of Ge2Sb2Te5 films studied by electrical resistance measurements , 2000 .

[11]  Zhitang Song,et al.  Improved thermal stability of N-doped Sb materials for high-speed phase change memory application , 2016 .

[12]  Songlin Feng,et al.  Nitrogen incorporated GeTe phase change thin film for high-temperature data retention and low-power application , 2011 .

[13]  Dolores C. Miller,et al.  Direct observation of amorphous to crystalline phase transitions in nanoparticle arrays of phase change materials , 2007 .

[14]  Myoung-Jae Lee,et al.  The role of contact resistance in GeTe and Ge2Sb2Te5 nanowire phase change memory reset switching current , 2015 .

[15]  B. Gholipour,et al.  Contact resistance measurement of Ge2Sb2Te5 phase change material to TiN electrode by spacer etched nanowire , 2014 .

[16]  Kinam Kim,et al.  Phase-Change Behavior of Stoichiometric Ge2Sb2Te5 in Phase-Change Random Access Memory , 2007 .

[17]  Y. Saito,et al.  Contact resistivity of amorphous and crystalline GeCu2Te3 to W electrode for phase change random access memory , 2016 .

[18]  N. Gennai,et al.  Micrometer-scale fabrication and assembly using focused ion beam , 2006 .

[19]  R. Fallica,et al.  Effect of nitrogen doping on the thermal conductivity of GeTe thin films , 2013 .

[20]  Bingchu Cai,et al.  Nitrogen-doped Ge2Sb2Te5 films for nonvolatile memory , 2005 .

[21]  Matthias Wuttig,et al.  Design Rules for Phase‐Change Materials in Data Storage Applications , 2011, Advanced materials.

[22]  Haralampos Pozidis,et al.  Recent Progress in Phase-Change Memory Technology , 2016, IEEE Journal on Emerging and Selected Topics in Circuits and Systems.