Scalable CGeSbTe-based phase change memory devices employing U-shaped cells

J. H. Park, J. H. Kim, Dae Hong Ko, Z. Wu, D. H. Ahn, S. O. Park, K. H. Hwang

Research output: Contribution to journalArticle


Phase change memory (PCM) that is operated on resistance changes caused by joule heating has been suggested as the next-generation memory for scaling since its programming current scales linearly. We propose a U-shaped cell design to further reduce the reset current in PCM devices, which enables easier and more efficient scaling than conventional PCMs. Simulation studies of heat transfer demonstrated that our U-shaped design with a dashed heater has a higher thermal efficiency of 4.97 K/μA compared to 3.36 K/μA in a lance cell with a ring heater for the same storage node. The reset current can be better scaled proportionate to k 2.0 in which the exponent is higher than the lance cell of k 1.5 in non-isotropic scaling. This better scalability is attributed to the small programming volume of the U-shaped cell, which was verified by transmission electron microscopy analysis. Furthermore, the cyclic endurance of the U-shaped cell was enhanced by 1 order of magnitude compared to a lance cell and the thinner CGeSbTe films reduced the reset current further. Our results show that a U-shaped cell is a highly promising design to scale reset current in next-generation PCM devices.

Original languageEnglish
Pages (from-to)141-146
Number of pages6
JournalThin Solid Films
Publication statusPublished - 2017 Jul 31


All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

Cite this

Park, J. H., Kim, J. H., Ko, D. H., Wu, Z., Ahn, D. H., Park, S. O., & Hwang, K. H. (2017). Scalable CGeSbTe-based phase change memory devices employing U-shaped cells. Thin Solid Films, 634, 141-146.