Ferroelectric-Assisted Dual-Switching Speed DRAM–Flash Hybrid Memory

This paper presents a novel one-transistor low-voltage DRAM-Flash hybrid memory. The proposed device integrates ferroelectric thin film and nonvolatile charge injection, and demonstrates two modes of operations: 1) a fast (10-100 ns) DRAM mode with ~ 103 s of retention, associated with ferroelectric switching, and 2) a slower (0.1-1 ms) Flash mode with long retention time, from charge tunneling into the floating nodes. The time evolution of the electric field in the ferroelectric and the tunnel oxide is shown to naturally establish the two-step mechanism during the program operation. The complementary characteristics of ferroelectric switching and gate-charge injection enable low-voltage program/erase (±8 V), reasonable memory window (0.8 V), and long retention time. Devices were fabricated with the lead zirconatetitanate thin film as the ferroelectric layer and Au nanocrystals for gate-injected electron storage. Pulsed programming measurements were also performed to distinguish the memory window obtained from the two mechanisms in DRAM and Flash operations.

[1]  B. Silverman,et al.  Depolarization fields in thin ferroelectric films , 1973 .

[2]  Z. Weinberg,et al.  On tunneling in metal‐oxide‐silicon structures , 1982 .

[3]  P. V. Dressendorfer,et al.  Device modeling of ferroelectric capacitors , 1990 .

[4]  H. Duiker,et al.  Grain-size effects in ferroelectric switching , 1991 .

[5]  M. Sayer,et al.  Crystallization of sputtered lead zirconate titanate films by rapid thermal processing , 1992 .

[6]  Sandip Tiwari,et al.  Volatile and non-volatile memories in silicon with nano-crystal storage , 1995, Proceedings of International Electron Devices Meeting.

[7]  A. Sheikholeslami,et al.  Transient modeling of ferroelectric capacitors for nonvolatile memories , 1996, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[8]  Orlando Auciello,et al.  Nanoscale investigation of fatigue effects in Pb(Zr,Ti)O3 films , 1996 .

[9]  Denis Remiens,et al.  Ferroelectric properties of PZT thin films prepared by sputtering with stoichiometric single oxide target: Comparison between conventional and rapid thermal annealing , 1997 .

[10]  James F. Scott,et al.  A model for fatigue in ferroelectric perovskite thin films , 2000 .

[11]  J. Bu,et al.  On the go with SONOS , 2000 .

[12]  Saied N. Tehrani,et al.  Recent developments in magnetic tunnel junction MRAM , 2000 .

[13]  A. Chin,et al.  Stack gate PZT/Al2O3 one transistor ferroelectric memory , 2001, IEEE Electron Device Letters.

[14]  U. Gösele,et al.  Polarization imprint and size effects in mesoscopic ferroelectric structures , 2001 .

[15]  Tengyu Ma,et al.  Why is nonvolatile ferroelectric memory field-effect transistor still elusive? , 2002, IEEE Electron Device Letters.

[16]  G. Pei,et al.  Metal nanocrystal memories. I. Device design and fabrication , 2002 .

[17]  A. Tagantsev,et al.  Non-Kolmogorov-Avrami switching kinetics in ferroelectric thin films , 2002 .

[18]  G. Pei,et al.  Metal nanocrystal memories-part II: electrical characteristics , 2002 .

[19]  The electrical properties of Metal-Ferroelectric (PbZr0.53Ti0.47O3)-Insulator-Silicon (MFIS) capacitors with different insulator materials , 2005 .

[20]  P. Juan,et al.  The charge trapping effect of metal-ferroelectric (PbZr0.53Ti0.47O3)-insulator (HfO2)-silicon capacitors , 2005 .

[21]  Edwin C. Kan,et al.  Self-assembly of metal nanocrystals on ultrathin oxide for nonvolatile memory applications , 2005 .

[22]  J.Y. Lee,et al.  A New Metal–Ferroelectric$(hboxPbZr_0.53hboxTi_0.47hboxO_3)$–Insulator$(hboxDy_2hboxO_3)$–Semiconductor (MFIS) FET for Nonvolatile Memory Applications , 2006, IEEE Electron Device Letters.

[23]  Tuo-Hung Hou,et al.  Design Optimization of Metal Nanocrystal Memory—Part II: Gate-Stack Engineering , 2006, IEEE Transactions on Electron Devices.

[24]  T. Noh,et al.  Domain switching kinetics in disordered ferroelectric thin films. , 2007, Physical review letters.

[25]  K. Prall.  Scaling Non-Volatile Memory Below 30nm , 2007, 2007 22nd IEEE Non-Volatile Semiconductor Memory Workshop.

[26]  S. Sakaia,et al.  Highly Scalable Fe(Ferroelectric)-NAND Cell with MFIS(Metal-Ferroelectric-Insulator-Semiconductor) Structure for Sub-10nm Tera-Bit Capacity NAND Flash Memories , 2008, 2008 Joint Non-Volatile Semiconductor Memory Workshop and International Conference on Memory Technology and Design.

[27]  Tuo-Hung Hou,et al.  Statistical Metrology of Metal Nanocrystal Memories With 3-D Finite-Element Analysis , 2009, IEEE Transactions on Electron Devices.

[28]  Hiroshi Ishiwara,et al.  Capacitance-voltage and retention characteristics of Pt/SrBi2Ta2O9/HfO2/Si structures with various buffer layer thickness , 2009 .

[29]  N. Righos,et al.  A stackable cross point Phase Change Memory , 2009, 2009 IEEE International Electron Devices Meeting (IEDM).

[30]  Fabrication and characterization of metal-ferroelectric (PbZr0.6Ti0.4O3)-insulator (La2O3)-semiconductor capacitors for nonvolatile memory applications , 2009 .

[31]  Veena Misra,et al.  Ultimate scalability of TaN metal floating gate with incorporation of high-K blocking dielectrics for Flash memory applications , 2010, 2010 International Electron Devices Meeting.

[32]  U. Böttger,et al.  Ferroelectricity in hafnium oxide thin films , 2011 .

[33]  Lothar Frey,et al.  Ferroelectricity in yttrium-doped hafnium oxide , 2011 .

[34]  Y. Nishitani,et al.  Correlated motion dynamics of electron channels and domain walls in a ferroelectric-gate thin-film transistor consisting of a ZnO/Pb(Zr,Ti)O3 stacked structure , 2011 .

[35]  Minghua Tang,et al.  Impact of HfTaO Buffer Layer on Data Retention Characteristics of Ferroelectric-Gate FET for Nonvolatile Memory Applications , 2011, IEEE Transactions on Electron Devices.

[36]  O. Richard,et al.  10×10nm2 Hf/HfOx crossbar resistive RAM with excellent performance, reliability and low-energy operation , 2011, 2011 International Electron Devices Meeting.

[37]  E. Kan,et al.  A Ferroelectric and Charge Hybrid Nonvolatile Memory—Part I: Device Concept and Modeling , 2012, IEEE Transactions on Electron Devices.

[38]  Switching dynamics in ferroelectric-charge hybrid nonvolatile memory , 2012, 70th Device Research Conference.

[39]  E. Kan,et al.  A Ferroelectric and Charge Hybrid Nonvolatile Memory—Part II: Experimental Validation and Analysis , 2012, IEEE Transactions on Electron Devices.