Vol.30 No.4

Editorial Office


  • Journal of the Microelectronics and Packaging Society
  • Volume 30(3); 2023
  • Article


Journal of the Microelectronics and Packaging Society 2023;30(3):73-77. Published online: Nov, 9, 2023

Multi-Level FeRAM Utilizing Stacked Ferroelectric Structure

  • Seok Heon Kong, June Hyeong Kim, and Seul Ki Hong
    Seoul National University of Science and Technology, 232 Gongneung-ro, Buk-gu, Seoul 01811
Corresponding author E-mail: skhong@seoultech.ac.kr

In this study, we developed a Multi-level FeRAM (Ferroelectrics random access memory) device utilizing different ferroelectric materials and analyzed its operation through C-V analysis using simulations. To achieve Multi-level operation, we proposed an MFM (Multi-Ferroelectric Material) structure by depositing two different ferroelectric materials with distinct properties horizontally on the same bottom electrode and subsequently adding a gate electrode on top. By analyzing C-V peaks based on the polarization phenomenon occurring under different voltage conditions for the two materials, we confirmed the feasibility of achieving Multi-level operation, where either one or both of the materials can be polarized. Furthermore, we validated the process for implementing the proposed structure using semiconductor fabrication through process simulations. These results signify the significance of the new structure as it allows storing multiple states in a single memory cell, thereby greatly enhancing memory integration.

Keywords Ferroelectric, FeRAM, Multi-level, Memory, Polarization

  • D. A. Buck, "Ferroelectrics for Digital Information Storage and Switching, MIT, June, Report R-212 (1952)
  • W. I. Kinney, W. Shepherd, W. Miller, J. Evans and R. Womack, "A non-volatile memory cell based on ferroelectric storage capacitors", IEEE, DC, USA, 850-851 (1987)
  • D. Damjanovic, "Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics, Reports on Progress in Physics, 61(9), (1998)
  • U. Schroeder, M. H. Park, T. Mikolajick & C. S. Hwang, The fundamentals and applications of ferroelectric HfO2, Nature Reviews Materials, 7, 653-669 (2022)
  • K. Asari, Y. Mitsuyama, T. Onoye, I. Shirakawa, H. Hirano, T. Honda, T. Otsuki, T. Baba, T. Meng, "Multi-mode and multi-level technologies for FeRAM embedded reconfigurable hardware", IEEE, CA, USA, 106-107 (1999)
  • M. Jung, V. Gaddam, S. Jeon, A review on morphotropic phase boundary in fluorite-structure hafnia towards DRAM technology, Nano Convergence, 9(44) (2022)
  • M. M. Vopson, G. Caruntu, X. Tan, Polarization reversal and memory effect in anti-ferroelectric materials, Scripta Materialia, 128, 61-64 (2017)
  • L. D. Filip, L. Pintilie, V. Stancu, I. Pintilie, "Simulation of the capacitance-voltage characteristic in the case of epitaxial ferroelectric films with Schottky contacts, Thin Solid Films, 592(Part A), 200-206 (2015)
  • J. Muller, U. Schroder, T. S. Boscke, I. Muller, U. Bottger, L. Wilde, J. Sundqvist, M. Lemberger, P. Kucher, T. Mikolajick, L. Frey, "Ferroelectricity in yttrium-doped hafnium oxide", J. Appl. Phys., 110(11), 114113 (2011)
  • T. Olsen; U. Schroder; S. Muller; A. Krause; D. Martin; A. Singh; J. Muller; M. Geidel; T. Mikolajick, "Co-sputtering yttrium into hafnium oxide thin films to produce ferroelectric properties", Appl. Phys. Lett., 101(8), 082905 (2012)
  • N.-H. Kim, P.-J. Ko, S. K. Kang, W.-S. Lee, "Platinum chemical mechanical polishing (CMP) characteristics for high density ferroelectric memory applications", Microelectronic Engineering, 84(11), 2702-2706 (2007)
  • G. E. Menk, S. B. Desu, W. Pan & D. P. Vijay, "Dry Etching Issues in the Integration of Ferroelectric Thin Film Capacitors", MRS Online Proceedings Library, 433, 189-200 (1996)
  • W. E. Frank, "Approaches for patterning of aluminum", Microelectronic Engineering, 33(1-4), 85-100 (1997)