摘要:

A set of criteria is presented, based on the polarization versus electric field hysteresis characteristics, which can be used to reveal a tendency towards imprint failure in ferroelectric capacitors. A series of pulsed voltage waveforms, generated by the RT66A ferroelectric tester, are utilized to validate our established criteria for the tendency towards imprinting. The tests have been performed on hetero-structure Pb(ZrxTi1−x)O3(PZT)-based capacitors produced by a pulsed laser ablation depositon technique (PLAD). The loss of retained charge in the ferroelectric capacitors is considered in light of the imprint test methodology. Rates of retention loss and imprint are extracted from the experimental data and treated as separate processes that lead to device failure. The rate of approach towards imprint failure is found to be influenced by the magnitude of the read pulse.

ISSN:1058-4587    

DOI:10.1080/10584589408223884

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Lanthanum-modified lead zirconate titanate (PLZT) thin films have been grown on Pt/SiO2/Si substrate at 650[ddot]C by metalorganic chemical vapor deposition. The relative dielectric constant increased as the La content was increased up to about 5 atomic percent (at%). The remanent polarization and coercive field decreased from 30 to 20 μC/cm2and from 53 to 30 kV/cm, respectively, with increasing La content in the range of 0–13 at%. The leakage current of PLZT film was 3 × 10−9A/cm2at an applied voltage of 3 V. The degradation of switched charge density of PLZT film was not observed even at 2 × 1011cycles.

ISSN:1058-4587    

DOI:10.1080/10584589408223885

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The paper presents the new method of mathematical treatment which allows to extract essential information about domain kinetics in polycrystal films from the traditional measurements of switching current. This information can not be obtained within the commonly used treatment. The method was verified by computer simulation and direct experiments in model single crystals.

ISSN:1058-4587    

DOI:10.1080/10584589408223886

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The influence of heat treatment and substrate materials on PLT thin films by sol-gel processing has been researched. Epitaxial growth PLT thin films with perovskite-type structure on sapphire, SrTiO3and MgO single crystal substrates have been prepared. The epitaxial relations are (100)PLT28/(100)SrTiO3, (111)PLT28//(0001)sapphire and (100)PLT14//(100)MgO. The PLT polycrystal thin films with perovskite-type structure on Si single crystal and quartz glass substrates have been prepared. The remanent polarization Pr and the coercive field Ec of PLT15 ceramic thin films are 7.7 μc/cm2and 34 kv/cm at 4 KHz respectively. The optical transmittance of PLT28 ceramic thin films within the wavelength range of λ = 500–1000 nm is approximately 80%.

ISSN:1058-4587    

DOI:10.1080/10584589408223887

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

PLZT thin films of composition 2/55/45 (La/Zr/Ti) were spin coated from acetate precursors and crystallized by rapid thermal processing (RTP) and conventional furnace pyrolysis (CFP). One experiment isolating the effects of thermal processing from deposition technique involved a comparison of rapid thermally processed films, produced with a computer controlled automatic spin coat reactor/analyzer, with conventional furnace pyrolyzed films, fabricated manually using a photoresist spin technique. Heating rates of at least 70[ddot]C per second for RTP versus 35[ddot]C per second for CFP yielded differences in film properties with thermal processing technique. All of the films were spun on Pt-coated Si substrates and were fired at 700[ddot]C for 15 total minutes; however, different firing schedules were utilized with variable individual layer firing times and post-anneal times. These variable firing schedules also yielded noticeable differences in film properties. Film thickness, measured with a laser ellipsometer, ranged from 0.4 to 0.5 μm. RTP thin films exhibited improved crystallinity, smaller grain size and better saturated hysteresis loops than CFP films. Higher dielectric constants of 715–1700 and lower coercive fields of 34–64 kV/cm were also observed in the RTP films compared to 600–740 and 63–104 kV/cm, respectively, for CFP films.

ISSN:1058-4587    

DOI:10.1080/10584589408223888

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper presents general transmission electron microscopy observations of polymeric sol-gel derived PZT(52/48) thin films that were heat treated in a conventional furnace for 1 hour at 700[ddot]C. Results from high resolution TEM, EDS and EELS are also included. The thin films revealed a complex microstructure with dispersed nanocrystalline PbO second phase, embedded porosity, local chemical inhomogeneities, and residual organics. Intricate ferroelectric domain configurations were observed in the thin film grains, which were found to be sensitive to continuous electron beam irradiation. Some artifacts intrinsic to transmission electron microscopy are outlined and their consequences discussed.

ISSN:1058-4587    

DOI:10.1080/10584589408223889

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The deposition of single phase perovskite lead titanate thin films by planar multi-target sputtering on silicon substrates covered with a thin Pt bottom electrode has been investigated. The films exhibited nearly random crystallographic orientation. The films are self polarized, that means they exhibited pyroelectric currents without poling treatment. After additional furnace annealing and poling the pyroelectric coefficient was 1.7.10−4C/m2K. The annealing also reduced the dielectric loss tan δ from 0.05 to 0.01. The temperature measurement for calculation of the pyroelectric coefficient was performed by measuring the resistance of the bottom and top electrode via the van der Pauw method and calibration with a thermo chuck.

ISSN:1058-4587    

DOI:10.1080/10584589408223890

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An electronically programmable mass-memory is demonstrated with a projected density capability in excess of 4.5.104bits/mm2, which possesses a nondestructive readout. It is based on the principle of a programmable voltage variable capacitor (VARICAP) and utilizes a ferroelectric thin film of (Ba,Sr)TiO3deposited by sputtering on a single crystal Si substrate.

ISSN:1058-4587    

DOI:10.1080/10584589408223891

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Since composition is an important parameter affecting the dielectric properties in paraelectric SrTiO3layers, composition is determined by Rutherford backscattering spectrometry (RBS) measurement. In this measurement, specifically for achieving precise composition measurement, the RBS spectra of Sr, Ti and O must be separated individually. This spectrum separation can only be attained when thin (800 A[ddot] thick) SrxTiOylayers are deposited on graphite substrate. The measurement is performed for layers deposited at different O2partial pressure ratios and sputtering pressures. This measurement indicates that composition of O, y, in SrxTiOylayer decreases from 3.7 to 2.7 with the decrease of O2partial pressure raito, R(=O2/O2+ Ar) from 1.0 to 0.83. Composition of Sr, x, also changes from 1.1 to 0.6 with this change. With the decrease of sputtering pressure from 10 to 5 mTorr, however, composition, y, is held at 2.7 and only the composition, x, increases from 0.6 to 1.1. This composition measurement is useful for the deposition of optimized dielectric layer employed in the charge storage capacitor.

ISSN:1058-4587    

DOI:10.1080/10584589408223892

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Three types of the photomechanical effects have been studied in BaTiO3and PbTiO3like crystals subjected to local mechanical stresses, namely, the photodomain effect, photomechanical effect and photo-mechanic-ferroelectric effect. All the effects studied are rooted in the interaction of the released current photocarriers with various microstructural elements of the crystal, i.e. the 90-domain walls, dislocations and cracks being formed.

ISSN:1058-4587    

DOI:10.1080/10584589408223893

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor