Structure and Device Characteristics of SrBi2Ta2O9-Based Nonvolatile Random-Access Memories

MRS Bulletin ◽  
1996 ◽  
Vol 21 (7) ◽  
pp. 33-39 ◽  
Author(s):  
J.F. Scott ◽  
F.M. Ross ◽  
C.A. Paz de Araujo ◽  
M.C. Scott ◽  
M. Huffman
Keyword(s):  
Lead Zirconate Titanate ◽  
Barium Strontium Titanate ◽  
Paradigm Shift ◽  
Random Access ◽  
Lead Zirconate ◽  
Dielectric Constants ◽  
Barium Strontium ◽  
Stored Information ◽  
Ferroelectric Random Access Memories ◽  
Ferroelectric Capacitors

Recently there has been a paradigm shift in nonvolatile computer memories from silicon-technology-based EEPROMs (electrically erasable, programmable read-only memories) to devices in which the stored information is coded into + and − polarizations in thin-film ferroelectric capacitors. Such devices have read and erase/rewrite speeds of the order of 1–35 ns, many orders of magnitude faster than the erase/rewrite speeds of the best EEPROMs (Table I). However, fundamental questions concerning their lifetimes had delayed full commercialization. Because ferroelectrics normally have extremely large dielectric constants, their use as nonswitching capacitors in dynamic random-access memories (DRAMs) is also rapidly evolving. The majority of studies to date have emphasized lead zirconate titanate (PZT)-based capacitors for nonvolatile ferroelectric random-access memories (NVFRAMs) and barium strontium titanate-based capacitor DRAMs (see Table II).

Schottky Barrier Heights of Tantalum Oxide, Barium Strontium Titanate, Lead Zirconate Titanate and Strontium Bismuth Tantalate

1998 ◽  
Vol 541 ◽  
Author(s):  
J Robertson ◽  
C W Chen
Keyword(s):  
Schottky Barrier ◽  
Strontium Titanate ◽  
Lead Zirconate Titanate ◽  
Barium Strontium Titanate ◽  
Lead Zirconate ◽  
Strontium Bismuth Tantalate ◽  
Barrier Heights ◽  
Barium Strontium ◽  
Zirconate Titanate ◽  
Titanate Lead

AbstractSchottky barrier heights of various metals on tantalum pentoxide, barium strontium titanate, lead zirconate-titanate and strontium bismuth tantalate have been calculated as a function of metal work function. These oxides have a dimensionless Schottky barrier pinning factor, S, of 0.28 – 0.4 and not close to 1, because S is controlled by the Ti-O type bonds not Sr-O type bonds, as assumed previously. Band offsets on silicon are asymmetric with much smaller offset at the conduction band, so that Ta2O5 and barium strontium titanate (BST) are relatively poor barriers to electrons on Si.

Dielectric properties of lead zirconate titanate thin films seeded with barium strontium titanate nanoparticles

2005 ◽  
Vol 471 (1-2) ◽  
pp. 71-75 ◽  
Author(s):  
Tomokazu Tanase ◽  
Yoshio Kobayashi ◽  
Toshihide Nabatame ◽  
Takao Miwa ◽  
Mikio Konno
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Strontium Titanate ◽  
Lead Zirconate Titanate ◽  
Barium Strontium Titanate ◽  
Lead Zirconate ◽  
Barium Strontium ◽  
Zirconate Titanate

Fatigue-free La-modified Pb(Zr, Ti)O3 capacitors using aseed layer

2002 ◽  
Vol 17 (8) ◽  
pp. 1884-1887 ◽  
Author(s):  
Santiranjan R. Shannigrahi ◽  
Sun-Hwa Lee ◽  
Hyun M. Jang
Keyword(s):  
Lead Zirconate Titanate ◽  
Coercive Field ◽  
Seed Layer ◽  
Random Access ◽  
Lead Zirconate ◽  
Si Substrates ◽  
Pt Electrodes ◽  
Long Time ◽  
Free Behavior ◽  
Ferroelectric Random Access Memories

The development of lead zirconate titanate (PZT)-based capacitors using common Pt electrodes has been a long-time goal of ferroelectric random access memories (FRAM).In this work, a series of Pb1−xLax(Zr0.55Ti0.45)O3 capacitors (for 0.01 < x < 0.05) having fatigue-free characteristics have been grown on Pt/ Ti/SiO2/Si substrates. Typically 2–3 mol% La-modified PZT capacitors fabricated at 580 °C by applying a PZT seed layer exhibited fatigue-free behavior up to 6.5 × 1010 switching cycles, a low coercive field of 50–55 kV/cm, and a stable charge retention profile with time, all of which assure their suitability for the future nonvolatile FRAM.

Sign in / Sign up

Export Citation Format

Share Document