Role of the Electrode Morphology, Thickness and Orientation in the Ferroelectric Performance of Epitaxial Pb(Zr,Ti)O3 Thin Films

AbstractA comparison of pulsed laser deposited PbZr0.53Ti0.47O3 (PZT) thin film capacitors with SrRuO3 (SRO) and LaNiO3 (LNO) electrodes on (001) yttria-stabilized zirconia (YSZ) and lattice matched (001) LaAlO3 substrates is presented. Both electrode materials allow for the formation of ferroelectric capacitors with large remnant polarization (20-30 μC/cm2) and negligible fatigue, although slight differences arise regarding the promotion of either the rhombohedral or tetragonal phases of PZT. Far more crucial seems to be the tendency of SrRuO3 to develop a rougher surface at either small (<30 nm) or large thickness (>100 nm), and on YSZ substrates. In those cases a highly defective and possibly low dielectric interface forms between the electrode and the ferroelectric layer, resulting in greatly degraded ferroelectric performance. LaNiO3 is free from these limitations except for the cracks forming at very large thickness (>300 nm), and therefore appears as a more versatile electrode material.

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Correlations Among Degradations in Lead Zirconate Titanate thin Film Capacitors

MRS Proceedings ◽

10.1557/proc-310-165 ◽

1993 ◽

Vol 310 ◽

Cited By ~ 69

Author(s):

In K. Yoo ◽

Seshu B. Desu ◽

Jimmy Xing

Keyword(s):

Thin Film ◽

Leakage Current ◽

Lead Zirconate Titanate ◽

Oxygen Vacancies ◽

Lead Zirconate ◽

Electrical Degradation ◽

Zirconate Titanate ◽

Thin Film Capacitors ◽

Pzt Thin Film ◽

Degradation Properties

AbstractMany attempts have been made to reduce degradation properties of Lead Zirconate Titanate (PZT) thin film capacitors. Although each degradation property has been studied extensively for the sake of material improvement, it is desired that they be understood in a unified manner in order to reduce degradation properties simultaneously. This can be achieved if a common source(s) of degradations is identified and controlled. In the past it was noticed that oxygen vacancies play a key role in fatigue, leakage current, and electrical degradation/breakdown of PZT films. It is now known that space charges (oxygen vacancies, mainly) affect ageing, too. Therefore, a quantitative ageing mechanism is proposed based on oxygen vacancy migration under internal field generated by either remanent polarization or spontaneous polarization. Fatigue, leakage current, electrical degradation, and polarization reversal mechanisms are correlated with the ageing mechanism in order to establish guidelines for simultaneous degradation control of PZT thin film capacitors. In addition, the current pitfalls in the ferroelectric test circuit is discussed, which may cause false retention, imprint, and ageing.

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Grain-Size-Dependent Thermal Transport Properties in Nanocrystalline Yttria-Stabilized Zirconia

MRS Proceedings ◽

10.1557/proc-703-v4.7 ◽

2001 ◽

Vol 703 ◽

Cited By ~ 3

Author(s):

Ho-Soon Yang ◽

J.A. Eastman ◽

L.J. Thompson ◽

G.-R. Bai

Keyword(s):

Grain Boundaries ◽

Thermal Transport ◽

Chemical Vapor ◽

Yttria Stabilized Zirconia ◽

Organic Chemical ◽

Stabilized Zirconia ◽

Size Dependent ◽

Metal Organic ◽

Organic Chemical Vapor Deposition

ABSTRACTUnderstanding the role of grain boundaries in controlling heat flow is critical to the success of many envisioned applications of nanocrystalline materials. This study focuses on the effect of grain boundaries on thermal transport behavior in nanocrystalline yttria-stabilized zirconia (YSZ) coatings prepared by metal-organic chemical vapor deposition.

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Investigation of the Role of Carbonylchemistry to Pattern Platinum Electrodes

MRS Proceedings ◽

10.1557/proc-688-c5.6.1 ◽

2001 ◽

Vol 688 ◽

Author(s):

St. Schneider ◽

H. Kohlstedt ◽

R. Waser

Keyword(s):

Carbon Monoxide ◽

Etch Rate ◽

Noble Metals ◽

Electrode Materials ◽

In Situ Monitoring ◽

Platinum Electrodes ◽

Process Chemistry ◽

Dimension Control ◽

Axis Position

AbstractNoble metals like platinum or irdium are used as electrode materials in DRAM or FRAM devices. Their etch process is a challenge as conventional, sputter driven etch processes either result in redeposition problems (fences) or in a severe sloping (loss of dimension control) and are not acceptable for high density integration architectures. The high temperature etch regime offers a solution by increasing the chemical etch component and thus the volatility of the etch products.As previously reported, the platinum etch rate increases exponentially for a chlorine etch process with increasing wafer temperature. In this study we investigate the particular role of carbon monoxide in a Cl2/CO etch process. We find that carbon monoxide additions to a chlorine process boost the chemical component of the platinum etch rate very significantly, exceeding the effects in the chlorine only process regime by far. Additionally we compare these results with a Cl2/O2 and a Cl2/CO2 process chemistry, which are not found to be particularly beneficial.To better understand the etch process we use an energy dispersive quadrupole mass spectrometer for in situ monitoring, attached to the chamber at two different locations. We are able to position the probe orifice at the place of the wafer electrode, to record ion energy and ion mass spectra of species impinging on the wafer plane. A second off axis position allows for etch product monitoring.

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Characterisation of the fatigued state of ferroelectric PZT thin-film capacitors

Microelectronic Engineering ◽

10.1016/0167-9317(95)00133-6 ◽

1995 ◽

Vol 29 (1-4) ◽

pp. 145-148 ◽

Cited By ~ 45

Author(s):

E.L. Colla ◽

A.L. Kholkin ◽

D. Taylor ◽

A.K. Tagantsev ◽

K.G. Brooks ◽

...

Keyword(s):

Thin Film ◽

Thin Film Capacitors ◽

Pzt Thin Film

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Synchrotron X-ray Microdiffraction Images of Polarization Switching in Epitaxial PZT Capacitors with Pt and SrRuO3 Top Electrodes

MRS Proceedings ◽

10.1557/proc-784-c6.4 ◽

2003 ◽

Vol 784 ◽

Author(s):

Dal-Hyun Do ◽

Dong Min Kim ◽

Chang-Beom Eom ◽

Eric M. Dufresne ◽

Eric D. Isaacs ◽

...

Keyword(s):

Thin Film ◽

Bottom Electrode ◽

Sputter Deposition ◽

Ferroelectric Polarization ◽

X Rays ◽

X Ray ◽

Pzt Film ◽

Thin Film Capacitors ◽

Pzt Thin Film ◽

Switchable Polarization

ABSTRACTThe evolution of stored ferroelectric polarization in PZT thin film capacitors was imaged using synchrotron x-ray microdiffraction with a submicron-diameter focused incident x-ray beam. To form the capacitors, an epitaxial Pb(Zr,Ti)O3 (PZT) thin film was deposited on an epitaxially-grown conductive SrRuO3 (SRO) bottom electrode on a SrTiO3 (STO) (001) substrate. Polycrystalline SRO or Pt top electrodes were prepared by sputter deposition through a shadow mask and subsequent annealing. The intensity of x-ray reflections from the PZT film depended on the local ferroelectric polarization. With 10 keV x-rays, regions of opposite polarization differed in intensity by 26% in our PZT capacitor with an SRO top electrode. Devices with SRO electrodes showed just a 25% decrease in the remnant polarization after 107 switching cycles. In devices with Pt top electrodes, however, the switchable polarization decreased a by 70% after only 5×104 cycles.

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Breakdown mechanisms in PZT thin film capacitors

Integrated Ferroelectrics ◽

10.1080/10584589508013598 ◽

1995 ◽

Vol 11 (1-4) ◽

pp. 269-275 ◽

Cited By ~ 7

Author(s):

In Kyeong Yoo ◽

Chang Jung Kim ◽

Seshu B. Desu

Keyword(s):

Thin Film ◽

Thin Film Capacitors ◽

Pzt Thin Film

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Inorganic Electrolytes in Supercapacitor

Materials Research Foundations - Supercapacitor Technology ◽

10.21741/9781644900499-2 ◽

2019 ◽

Keyword(s):

Energy Storage ◽

Electrochemical Performance ◽

Power Density ◽

High Power ◽

Electrode Materials ◽

Storage Systems ◽

Research Work ◽

Wide Operating ◽

Charge Discharge

Supercapacitors are considered promising energy storage systems due to their high power density, fast charge-discharge, long service lifetime, wide operating temperature range and excellent capacitance retention. The electrochemical performance of the supercapacitors depends upon numerous factors such as nature of electrode materials, type of electrolyte and separator thickness, etc. Among these factors, electrolyte used in supercapacitor plays an important role in deciding final characteristics of supercapacitors. In recent decades, tremendous research work has been on the development of novel electrolytes and electrode/electrolyte configurations. In this chapter, we aimed to focus on the role of inorganic electrolytes used in supercapacitors.

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