Low-Voltage Pb(Zr,Ti)O3 Film Capacitors: Control of Charge Relaxation at the Interfaces

1999 ◽  
Vol 596 ◽  
Author(s):  
I. Stolichnov ◽  
A. Tagantsev ◽  
S. Gentil ◽  
S. Hiboux ◽  
P. Muralt ◽  
...  
Keyword(s):  
Size Effects ◽  
Low Voltage ◽  
Charge Injection ◽  
Fatigue Performance ◽  
Charge Relaxation ◽  
Positive Effects ◽  
Pzt Film ◽  
Electrode Interface ◽  
Ferroelectric Capacitors ◽  
Ferroelectric Switching

AbstractIt is suggested that the processes of charge injection and entrapment at the interfacial layer of Pb(Zr,Ti)O3 (PZT) film capacitors are responsible for both polarization fatigue and size effects on ferroelectric switching. The study of the charge injection by analyzing the dependence of coercive field on maximum polarization shows that there is a direct relationship between the charge injection properties and fatigue performance. Based on our results, we conclude that enhancement of charge relaxation at the interfaces of PZT capacitors results in two positive effects: improvement of polarization fatigue performance and suppression of size effects on ferroelectric switching, which are detrimental for low-voltage PZT film capacitors.This idea has been implemented experimentally by introducing a thin RuO2 layer into the top-electrode interface of the Pt/PZT/Pt capacitor. PZT film capacitors of 100–170 nm thickness prepared in this way exhibited substantially improved fatigue in combination with weak size effects, which allows reduction of the operation voltage down to 0.8 V without degradation of the hysteresis properties. Our results show that the control of charge relaxation at the interface is a key issue for development of the low-voltage ferroelectric capacitors.

Downscaling of Pb(Zr,Ti)O3 film thickness for low-voltage ferroelectric capacitors: Effect of charge relaxation at the interfaces

2000 ◽  
Vol 88 (4) ◽  
pp. 2154-2156 ◽  
Author(s):  
I. Stolichnov ◽  
A. Tagantsev ◽  
E. Colla ◽  
S. Gentil ◽  
S. Hiboux ◽  
...  
Keyword(s):  
Film Thickness ◽  
Low Voltage ◽  
Charge Relaxation ◽  
Ferroelectric Capacitors

Charge relaxation at the interfaces of low-voltage ferroelectric film capacitors: Fatigue endurance and size effects

2001 ◽  
Vol 258 (1) ◽  
pp. 221-230
Author(s):  
Igor Stolichnov ◽  
Alexander Tagantsev ◽  
Enrico Colla ◽  
Nava Setter
Keyword(s):  
Size Effects ◽  
Low Voltage ◽  
Ferroelectric Film ◽  
Charge Relaxation ◽  
Fatigue Endurance

Lead based ferroelectric capacitors for low voltage non-volatile memory applications

1998 ◽  
Vol 19 (1-4) ◽  
pp. 159-177 ◽  
Author(s):  
S. Aggarwal ◽  
A. S. Prakash ◽  
T. K. Song ◽  
S. Sadashivan ◽  
A. M. Dhote ◽  
...  
Keyword(s):  
Low Voltage ◽  
Non Volatile Memory ◽  
Volatile Memory ◽  
Memory Applications ◽  
Ferroelectric Capacitors

Reliability Properties of Low-Voltage Ferroelectric Capacitors and Memory Arrays

2004 ◽  
Vol 4 (3) ◽  
pp. 436-449 ◽  
Author(s):  
J.A. Rodriguez ◽  
K. Remack ◽  
K. Boku ◽  
K.R. Udayakumar ◽  
S. Aggarwal ◽  
...  
Keyword(s):  
Low Voltage ◽  
Memory Arrays ◽  
Ferroelectric Capacitors

scholarly journals The effect of unilateral thalamic deep brain stimulation on the vocal dysfunction in a patient with spasmodic dysphonia: interrogating cerebellar and pallidal neural circuits

2018 ◽  
Vol 128 (2) ◽  
pp. 575-582 ◽  
Author(s):  
Anujan Poologaindran ◽  
Zurab Ivanishvili ◽  
Murray D. Morrison ◽  
Linda A. Rammage ◽  
Mini K. Sandhu ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Neural Circuits ◽  
Rating Scale ◽  
Low Voltage ◽  
Spasmodic Dysphonia ◽  
High Frequency Stimulation ◽  
Vocal Function ◽  
Positive Effects ◽  
Deep Brain

Spasmodic dysphonia (SD) is a neurological disorder of the voice where a patient's ability to speak is compromised due to involuntary contractions of the intrinsic laryngeal muscles. Since the 1980s, SD has been treated with botulinum toxin A (BTX) injections into the throat. This therapy is limited by the delayed-onset of benefits, wearing-off effects, and repeated injections required every 3 months. In a patient with essential tremor (ET) and coincident SD, the authors set out to quantify the effects of thalamic deep brain stimulation (DBS) on vocal function while investigating the underlying motor thalamic circuitry.A 79-year-old right-handed woman with ET and coincident adductor SD was referred to our neurosurgical team. While primarily treating her limb tremor, the authors studied the effects of unilateral, thalamic DBS on vocal function using the Unified Spasmodic Dysphonia Rating Scale (USDRS) and voice-related quality of life (VRQOL). Since dystonia is increasingly being considered a multinodal network disorder, an anterior trajectory into the left thalamus was deliberately chosen such that the proximal contacts of the electrode were in the ventral oralis anterior (Voa) nucleus (pallidal outflow) and the distal contacts were in the ventral intermediate (Vim) nucleus (cerebellar outflow). In addition to assessing on/off unilateral thalamic Vim stimulation on voice, the authors experimentally assessed low-voltage unilateral Vim, Voa, or multitarget stimulation in a prospective, randomized, doubled-blinded manner. The evaluators were experienced at rating SD and were familiar with the vocal tremor of ET. A Wilcoxon signed-rank test was used to study the pre- and posttreatment effect of DBS on voice.Unilateral left thalamic Vim stimulation (DBS on) significantly improved SD vocal dysfunction compared with no stimulation (DBS off), as measured by the USDRS (p < 0.01) and VRQOL (p < 0.01). In the experimental interrogation, both low-voltage Vim (p < 0.01) and multitarget Vim + Voa (p < 0.01) stimulation were significantly superior to low-voltage Voa stimulation.For the first time, the effects of high-frequency stimulation of different neural circuits in SD have been quantified. Unexpectedly, focused Voa (pallidal outflow) stimulation was inferior to Vim (cerebellar outflow) stimulation despite the classification of SD as a dystonia. While only a single case, scattered reports exist on the positive effects of thalamic DBS on dysphonia. A Phase 1 pilot trial (DEBUSSY; clinical trial no. NCT02558634, clinicaltrials.gov) is underway at the authors' center to evaluate the safety and preliminary efficacy of DBS in SD. The authors hope that this current report stimulates neurosurgeons to investigate this new indication for DBS.

Resolving the Landauer paradox in ferroelectric switching by high-field charge injection

2009 ◽  
Vol 80 (2) ◽  
Author(s):  
An-Quan Jiang ◽  
Hyun Ju Lee ◽  
Cheol Seong Hwang ◽  
Ting-Ao Tang
Keyword(s):  
High Field ◽  
Charge Injection ◽  
Ferroelectric Switching

scholarly journals Voltage Shifts and Defect-Dipoles in Ferroelectric Capacitors

1996 ◽  
Vol 433 ◽  
Author(s):  
W. L. Warren ◽  
G. E. Pike ◽  
D. Dimos ◽  
K. Vanheusden ◽  
H.N. Al-Shareef ◽  
...  
Keyword(s):  
Charge Trapping ◽  
Spatial Location ◽  
Ferroelectric Materials ◽  
Electron Trapping ◽  
Defect Dipole ◽  
Electrode Interface ◽  
Dc Bias ◽  
Ferroelectric Capacitors ◽  
Lead Vacancy ◽  
Common Defect

AbstractWe review the processes and mechanisms by which voltage offsets occur in the hysteresis loop of ferroelectric materials. Simply stated, voltage shifts arise from nearinterfacial charge trapping in the ferroelectric. We show that the impetus behind voltage shifts in ferroelectric capacitors is the net polarization, with the net polarization being determined by the perovskite and the aligned defect-dipole components. Some common defect-dipoles in the PZT system are lead vacancy-oxygen vacancy complexes. One way to change the net polarization in the ferroelectric is to subject the PZT capacitor to a dc bias at elevated temperature; this process is spectroscopically shown to align defect-dipoles along the direction of the applied electric field. The alignment of defect-dipoles can strongly impact several material properties. One such impact is that it can lead to enhanced voltage shifts (imprint). It is proposed that the net polarization determines the spatial location of the asymmetrically trapped charge that are the cause for the voltage shifts. An enhanced polarization at one electrode interface can lead to larger voltage shifts since it lowers the electrostatic potential well for electron trapping, i.e., more electron trapping can occur. Defect-dipole alignment is also shown to increase the UV sensitivity of the ferroelectric.

Dependence of Thermally Stimulated Current in PZT Film Capacitors on PZT-Electrode Interface

2007 ◽  
Vol 357 (1) ◽  
pp. 243-247 ◽  
Author(s):  
Takashi Nishida ◽  
Takashi Takeda ◽  
Kiyoshi Uchiyama ◽  
Tadashi Shiosaki
Keyword(s):  
Thermally Stimulated Current ◽  
Pzt Film ◽  
Electrode Interface
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