Epitaxial LaNiO3Interlayers for Ferroelectric Memory Structures

1994 ◽  
Vol 341 ◽  
Author(s):  
J. D. Klein ◽  
A. Yen ◽  
S. L. Clauson
Keyword(s):  
Thin Films ◽  
Nonvolatile Memory ◽  
Remanent Polarization ◽  
Long Term Memory ◽  
Metallic Contact ◽  
Ferroelectric Capacitor ◽  
Wide Range ◽  
Memory Applications ◽  
Ferroelectric Capacitors

AbstractLaNiO3 thin films were utilized as metallic contact layers in ferroelectric capacitors. The LaNiO3 films were probably epitaxial when deposited atop (100) LaAlO3 substrates. They exhibited metallic resistivity over a wide range of temperature and oxygen partial pressure. Subsequent deposition of PZT and LaNiO3 thin films atop LaNiO3/LaAlO3 allowed realization of parallel-plate ferroelectric capacitor structures. The suitability of such devices for nonvolatile memory applications was surveyed through pulsed voltage testing. The observed 1-second remanent polarization exceeded 18 μC/cm2. Long-term memory was demonstrated for up to sixteen hours. No decrease in remanent polarization was apparent after more than 109 switching cycles.

Optical Band Gap Implications for Ferroelectric Memory Applications

1994 ◽  
Vol 361 ◽  
Author(s):  
J.D. Klein ◽  
S.L. Clauson
Keyword(s):  
Thin Films ◽  
Nonvolatile Memory ◽  
Remanent Polarization ◽  
Long Term Memory ◽  
X Ray Diffraction ◽  
Ferroelectric Capacitor ◽  
Wide Range ◽  
Ferroelectric Memory ◽  
Memory Applications

Metallic perovskite contact layers enable fatigue-resistant ferroelectric memory capacitors to be obtained. LaNiO3 films atop (100) LaAlO3 substrates exhibit metallic resistivity over a wide range of temperature and oxygen partial pressure. Subsequent deposition of PZT and LaNiO3 thin films atop LaNiO3/LaAlO3 provides parallel-plate ferroelectric capacitor structures. However, the quality of the PZT thin films cannot be reliably indicated by conventional means such as x-ray diffraction. Optical properties of the PZT layers were examined to discern differences in otherwise similar films. The suitability of Au/LaNiO3/PZT/LaNiO3/LaAlO3 devices for nonvolatile memory applications was surveyed through pulsed voltage testing. Observed 1-second remanent polarization (PR [1 sec]) exceeded 35μC/cm2. Long-term memory was demonstrated for up to sixteen hours. No decrease in remanent polarization was apparent after more than 2 × 1010 switching cycles.

Optical Non-Invasive Evaluation of Ferroelectric Films/Memory Capacitors

1994 ◽  
Vol 360 ◽  
Author(s):  
Sarita Thakoor ◽  
A. P. Thakoor ◽  
L. Eric Cross
Keyword(s):  
Thin Films ◽  
High Speed ◽  
Remanent Polarization ◽  
Strong Dependence ◽  
Direct Function ◽  
Ferroelectric Capacitor ◽  
Non Invasive ◽  
On Line ◽  
Ferroelectric Capacitors ◽  
Excellent Tool

AbstractNON-INVASIVE photoresponse (photocurrent/voltage, reflectance and transmittance) from ferroelectric thin films and memory capacitors, with its strong dependence not only on the remanent polarization, but also on the film microstructure, crystal orientation, and nature of the interfaces (state of formation/degradation, etc.) offers an excellent “tool” for probing the ferroelectric capacitors at virtually any stage of fabrication, including on-line quality control. In fact, simultaneous measurement of spectral photoresponse and spectral reflectance, as a distinctive signature of the device probed, is an ideal, high speed, non-invasive means of evaluation for such thin films at high spatial resolution (∼ 100 nm) using beam scanning. This paper discusses three aspects of such evaluation. First, the spectral transmittance of the film as a direct function of the microstructure, second, the use of band-gap illumination (365 nm) to condition a fatigued capacitor; and third, the optical E field interaction with the ferroelectric capacitor, yielding a high speed photoresponse which is related to the remanent polarization and the operational history (status of internal fields) of the ferroelectric capacitor. Combined, these different kinds of photoresponses provide a good signature of the device quality.

Electrical Measurement of Ferroelectric Capacitors for Non-Volatile Memory Applications

1990 ◽  
Vol 200 ◽  
Author(s):  
Norman Abt
Keyword(s):  
Remanent Polarization ◽  
Cmos Technology ◽  
Electrical Measurement ◽  
Ferroelectric Capacitor ◽  
Non Volatile Memory ◽  
In Series ◽  
Volatile Memory ◽  
Memory Applications ◽  
Silicon Cmos ◽  
Ferroelectric Capacitors

ABSTRACTModified lead titanate ferroelectdc thin films are currently utilized in conjunction with silicon CMOS technology for non-volatile memory applications. The electrical measurement of ferroelectric films has been common practice for many years but the parameters necessary for optimizing their use as memory have not been routinely recorded. Remanent polarization, spontaneous polarization and their change through fatigue and ageing are still the dominant parameters but the pulsing conditions of interest are driven by the circuit requirements. The operation of a memory circuit will be discussed along with implications for testing. Memory is written by applying a pulse to the capacitor. It is read by applying a pulse and sensing whether or not the polarization switched. Read and write pulses will apply different voltages to the ferroelectric capacitor in the circuit because a sense capacitor will be in series with it during the read. A new test, pulsed hysteresis, which is based on circuit operation will be presented. Parameter space of interest will also be discussed.

The physical and electrical characterizations of Cr-doped BiFeO3 ferroelectric thin films for nonvolatile memory applications

2015 ◽  
Vol 138 ◽  
pp. 86-90 ◽  
Author(s):  
Pi-Chun Juan ◽  
Jyh-Liang Wang ◽  
Tsang-Yen Hsieh ◽  
Cheng-Li Lin ◽  
Chia-Ming Yang ◽  
...  
Keyword(s):  
Thin Films ◽  
Nonvolatile Memory ◽  
Ferroelectric Thin Films ◽  
Memory Applications ◽  
Electrical Characterizations

Structural transformation of SbxSe100−x thin films for phase change nonvolatile memory applications

2005 ◽  
Vol 98 (1) ◽  
pp. 014904 ◽  
Author(s):  
M. J. Kang ◽  
S. Y. Choi ◽  
D. Wamwangi ◽  
K. Wang ◽  
C. Steimer ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Change ◽  
Structural Transformation ◽  
Nonvolatile Memory ◽  
Memory Applications

Thin PZT-Based Ferroelectric Capacitors on Flexible Silicon for Nonvolatile Memory Applications

2015 ◽  
Vol 1 (6) ◽  
pp. 1500045 ◽  
Author(s):  
Mohamed T. Ghoneim ◽  
Mohammed A. Zidan ◽  
Mohammed Y. Alnassar ◽  
Amir N. Hanna ◽  
Jurgen Kosel ◽  
...  
Keyword(s):  
Nonvolatile Memory ◽  
Memory Applications ◽  
Ferroelectric Capacitors

Noncoding RNAs and RNA Editing in Brain Development, Functional Diversification, and Neurological Disease

2007 ◽  
Vol 87 (3) ◽  
pp. 799-823 ◽  
Author(s):  
Mark F. Mehler ◽  
John S. Mattick
Keyword(s):  
Nervous System ◽  
Rna Editing ◽  
Neurological Diseases ◽  
Cell Types ◽  
State Transitions ◽  
Long Term Memory ◽  
Protein Coding ◽  
Continuous State ◽  
Wide Range

The progressive maturation and functional plasticity of the nervous system in health and disease involve a dynamic interplay between the transcriptome and the environment. There is a growing awareness that the previously unexplored molecular and functional interface mediating these complex gene-environmental interactions, particularly in brain, may encompass a sophisticated RNA regulatory network involving the twin processes of RNA editing and multifaceted actions of numerous subclasses of non-protein-coding RNAs. The mature nervous system encompasses a wide range of cell types and interconnections. Long-term changes in the strength of synaptic connections are thought to underlie memory retrieval, formation, stabilization, and effector functions. The evolving nervous system involves numerous developmental transitions, such as neurulation, neural tube patterning, neural stem cell expansion and maintenance, lineage elaboration, differentiation, axonal path finding, and synaptogenesis. Although the molecular bases for these processes are largely unknown, RNA-based epigenetic mechanisms appear to be essential for orchestrating these precise and versatile biological phenomena and in defining the etiology of a spectrum of neurological diseases. The concerted modulation of RNA editing and the selective expression of non-protein-coding RNAs during seminal as well as continuous state transitions may comprise the plastic molecular code needed to couple the intrinsic malleability of neural network connections to evolving environmental influences to establish diverse forms of short- and long-term memory, context-specific behavioral responses, and sophisticated cognitive capacities.

Effect of Deposition Temperature on I-V Characteristics of Vanadium Oxide Film

2012 ◽  
Author(s):  
X. Y. Wei ◽  
M. Hu ◽  
F. Wang ◽  
J. Wei ◽  
K. L. Zhang
Keyword(s):  
Thin Films ◽  
Vanadium Oxide ◽  
Photoelectron Spectroscopy ◽  
Nonvolatile Memory ◽  
Semiconductor Device ◽  
Oxide Thin Film ◽  
Reset Voltage ◽  
Switching Characteristics ◽  
Vanadium Oxide Thin Films ◽  
Memory Applications

In this paper, the effects of deposition temperatures on the resistive switching characteristics of polycrystalline vanadium oxide thin films have been investigated. VOx thin films were prepared by reactive sputtering at various deposition temperatures (RT, 250 °C, 350 °C, and 450 °C, respectively). X-ray photoelectron spectroscopy revealed the compositions of VOx thin films. Electrical switching has been observed in Cu(tip)/VOx/Cu memory units by Semiconductor Device Analyzer. Crystalline characterizations revealed that as-deposited (RT) film was amorphous, the films crystallized into different phases (e.g. VO2, V2O5, VO1.86 etc.) with increasing the deposition temperatures. The VOx memory units have low Vset and Vreset. Furthermore, their set voltage decreased from 1.52 V to 0.45 V and reset voltage decreased from 1.01 V to 0.41 V with increasing the deposition temperatures from 250 °C to 450 °C, respectively. The thin films have three orders of change in resistivity between ON-state and OFF-state except as-deposited film. The vanadium oxide thin film can be a promising material for low power nonvolatile memory applications.

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