摘要:

This paper presents the fabrication of an integrated optoelectronic circuit consisting of a waveguide and photodetector. Fabrication of the waveguides took place in a RIBE system with 1·5 sccm CH4/H2(60:40) and 0·5 sccm Ar. Wet etching defines the photodetector regions. The detection of surface damage is minimal, using a novel differential optical reflectance technique.

ISSN:1058-4587    

DOI:10.1080/10584589508012910

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The use of application-specific integrated circuits (ASICs) has become widespread; from use in sophisticated telecommunications equipment through to children's toys. However, aspects of design, fabrication and testing may not be as rigorous as for the standard components that they are replacing.

ISSN:1058-4587    

DOI:10.1080/10584589508012911

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Ferroelectric La doped PZT 60/40 thin films with uniform composition have been synthesized using metallo-organic precursor solutions. These metallo-organic precursors have been stored for more than four years and are very stable in ambient conditions, compared to the sol-gel solutions. The structural properties of these films have been studied using X-ray diffraction and atomic force microscopy. The excellent ferroelectric properties of the films, such as less than 10% polarization loss after 1011cycles, low leakage current of 3·06×10−12A at 2 V, and small separation of polarization peaks in a voltage loop by the small-signal measurement, are attributed to the high quality of the metalloorganic solutions used in this study, which have been carefully home-synthesized. The oxygen vacancy in the films was reduced by optimizing the annealing conditions, and to minimize the blocking oxygen vacancy at the interface by Pt electrodes a suitable amount of La ions was doped. We suggest that greater attention should be paid to the elimination/minimization of the oxygen vacancy in the ferroelectric PZT films instead of using oxide electrodes, which allow a relatively larger leakage current flowing through the films and the electrodes.

ISSN:1058-4587    

DOI:10.1080/10584589508012912

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Material used to form dielectrics in silicon technology are currently changing. For example intermetal dielectrics need to have a low dielectric constant and therefore a move away from conventional materials is occurring. DRAM's have an opposite requirement and for this reason metal oxide dielectrics are being pursued with a longer term view of using ferroelectric materials. The area of gate oxides is also one of review and we show in this paper that dielectrics formed in a nitric oxide ambient may be appropriate at least to the end of this century.

ISSN:1058-4587    

DOI:10.1080/10584589508012913

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Since the demonstration of current densities above 10 A/cm2, emitted from ferroelectric ceramic material, at CERN in 1988,1there has been a quickly growing interest in the developement of such electron beam sources. Through thorough examination properties of the phenomenon were established which are different as compared to conventional source behaviour. The efficiency of emission from ferroelectrics is not affected by the quality of the vacuum; one may even profit by gas amplification due to avalanche processes in the low-pressure gas regime or operate the source in a plasma environment. Emission of high currents take place without the need of an external extraction voltage, moreover, the electrons have an initial kinetic energy of up to several keV. This is caused by the generation of an high electric field in the material when switching the ferroelectric in a nanosecond time scale. Thus the rate of polarization change determines the electron yield. The structure of the electrode grid at the emitting ferroelectic surface defines the geometry of the electron beam; microsources as well as large area emitters are possible. Basic characteristics of the FEBS were reviewed;2original literature is cited there, too. The kinetics of the emission process was investigated and found to be closely related to the switching dynamics in the ferroelectric, respectively. This includes partial switching processes and polarization changes induced by a fast phase transition from a non-polar to the ferroelectric state. Electric field calculations of a commonly used emitter geometry were performed and support the understanding of the phenomenon.3At present, in approximately 20 laboratories all over the world electron emission from ferroelectrics is object of research and development. In the beginning, main applications were anticipated in the area of high energy physics and accelerator technology as high brightness sources for power microwave tubes, x-ray generation, free electron lasers, and injectors for linear accelerators. More recently, increasing efforts are made to aim at emission from ferroelectric thin films. Consistent with this are applications in micro-electronics and vacuum-electronic devices such as micro-triodes and flat panel displays. Most advanced is the use of electron emission from ferroelectrics as a charge injection trigger which initializes closing of a high-power gas switch in pseudo-spark geometry, developed for the CERN Large Hadron Collider (LHC)4.

ISSN:1058-4587    

DOI:10.1080/10584589508012914

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Degradations in ferroelectric capacitors are categorized as DC and AC types. In memory applications, AC type degradations appears to be more serious than those of DC type. Breakdown, for example, occurs earlier under AC operation than DC. AC type degradations were reviewed and induction period was also discussed extensively. An induction mechanism was proposed based on domain rearrangement under AC conditions.

ISSN:1058-4587    

DOI:10.1080/10584589508012915

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Comparison has been made between the microstructures and electrical properties of Pb0·95La0·05TiO3(PLT) thin films deposited on bare (100)MgO and on Pt/(100)MgO. Nearly perfect epitaxial PLT was grown on (100)MgO. (100)-oriented Pt film was obtained via coalescence of Pt islands formed on MgO. Highly c-axis oriented PLT thin film was successfully grown on the Pt bottom electrode with an electrically conductive network structure. High detectivity of 3·5 × 108and 2·6 × 108cm√Hz/W was obtained at 30 Hz without any poling treatments from the PLT/MgO- and PLT/Pt/MgO-based infrared detectors, respectively.

ISSN:1058-4587    

DOI:10.1080/10584589508012916

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Electron emission into vacuum from a thin plate of ferroelectric lead-zirconatetitanate (PZT) ceramic has been observed under the impression of electric field of pulse consisting of a pair of positive and negative voltages. The emission was observed at pressure lower than about 10−1Torr. The emitted charge increases with increasing the positive and the absolute negative voltages of the pulse and the collector voltage. The minimum absolute value of the negative pulse for electron emission is 30V when the positive voltage is larger than 150V. The maximum peak current density is 70A/cm2. It is considered from the electrode area and thickness dependences of the charge that electrons are emitted not only from the ceramic surface near the electrode edge but also through the thin metal electrode. The emitted charge per one pulse little depends on pulse frequency when it is less than 2kHz, and so the total current density can be enhanced by increasing the frequency. The emission is observed even at temperatures above Curie temperature. It is considered that the emission is induced by abrupt change of dielectric flux as well as the polarization reversal. Cathodoluminescence from phosphors excited by the emitted electrons has been observed.

ISSN:1058-4587    

DOI:10.1080/10584589508012917

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The integration of PZT ceramic thin films into the current technology of silicon-based integrated circuits is discussed. The most widespread and obvious applications are considered: memory ICs, parallel analog processors, and pyroelectric detectors.

ISSN:1058-4587    

DOI:10.1080/10584589508012918

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This paper reviews down-scaling limitations in CMOS devices, with a special emphasis on the possible application of ferroelectric materials. Ultimate limit in reduction of the thickness of gate oxide is found as the most important limitation. The possibility of replacing or enhancing the gate oxide by a ferroelectric material is critically considered in view of the desired properties of the silicon - to - gate insulator interface.

ISSN:1058-4587    

DOI:10.1080/10584589508012919

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor