An overview of the state of art in ferroelectric thin films is presented. First, we review applications: microsystems' applications, applications in high frequency electronics, and memories based on ferroelectric materials. The second section deals with materials, structure (domains, in particular), and size effects. Properties of thin films that are important for applications are then addressed: polarization reversal and properties related to the reliability of ferroelectric memories, piezoelectric nonlinearity of ferroelectric films which is relevant to microsystems' applications, and permittivity and loss in ferroelectric films-important in all applications and essential in high frequency devices. In the context of properties we also discuss nanoscale probing of ferroelectrics. Finally, we comment on two important emerging topics: multiferroic materials and ferroelectric one-dimensional nanostructures. (c) 2006 American Institute of Physics.

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Ferroelectric thin films: Review of materials, properties, and applications

This review paper summarizes recent advances in the quickly developing field of nanoscale ferroelectrics, analyses its current status and considers potential future developments. The paper presents a brief survey of the fabrication methods of ferroelectric nanostructures and investigation of the size effects by means of scanning probe microscopy. One of the focuses of the review will be the study of kinetics of nanoscale ferroelectric switching in inhomogeneous electrical and elastic fields. Another emphasis will be made on tailoring the electrical and mechanical properties of ferroelectrics with a viewpoint of fabrication of nanoscale domain structures.

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Nanoscale ferroelectrics: processing, characterization and future trends

Systems and methods for volume dimensioning packages are provided. A method of operating a volume dimensioning system may include the receipt of image data of an area at least a first three-dimensional object to be dimensioned from a first point of view as captured using at least one image sensor. The system can determine from the received image data a number of features in three dimensions of the first three-dimensional object. Based at least on part on the determined features of the first three-dimensional object, the system can fit a first three-dimensional packaging wireframe model about the first three-dimensional object. The system can display of an image of the first three-dimensional packaging wireframe model fitted about an image of the first three-dimensional object on a display device.

Volume dimensioning systems and methods

Our understanding of the ``long range'' electrodynamic, electrostatic, and polar interactions that dominate the organization of small objects at separations beyond an interatomic bond length is reviewed From this basic-forces perspective, a large number of systems are described from which one can learn about these organizing forces and how to modulate them The many practical systems that harness these nanoscale forces are then surveyed The survey reveals not only the promise of new devices and materials, but also the possibility of designing them more effectively

https://link.aps.org/pdf/10.1103/RevModPhys.82.1887

Long Range Interactions in Nanoscale Science.

Piezoresponse force microscopy (PFM) has emerged as a powerful and versatile tool for probing nanoscale phenomena in ferroelectric materials on the nanometer and micrometer scales. In this review, we summarize the fundamentals and recent advances in PFM, and describe the nanoscale electromechanical properties of several important ferroelectric ceramic materials widely used in memory and microelectromechanical systems applications. Probing static and dynamic polarization behavior of individual grains in PZT films and ceramics is discussed. Switching spectroscopy PFM is introduced as a useful tool for studying defects and interfaces in ceramic materials. The results on local switching and domain pinning behavior, as well as nanoscale fatigue and imprint mapping are presented. Probing domain structures and polarization dynamics in polycrystalline relaxors (PMN-PT, PLZT, doped BaTiO 3 ) are briefly outlined. Finally, applications of PFM to dimensionally confined ferro-electrics are demonstrated. The potential of PFM for studying local electromechanical phenomena in polycrystalline ferroelectrics where defects and other inhomogeneities are essential for the interpretation of their macroscopic properties is illustrated.

Electromechanical Imaging and Spectroscopy of Ferroelectric and Piezoelectric Materials: State of the Art and Prospects for the Future

We report a resistive probe that detects electric field by field-induced resistance changes in a small resistive region at the apex of the tip and demonstrate a method of imaging ferroelectric domains at high speed, which is named scanning resistive probe microscopy (SRPM). We designed and fabricated the probe by self-aligning process that readily implemented the resistive region at the tip apex. In order to measure the field sensitivity, we contacted the probe with a thermally oxidized silicon sample and detected a 0.3% resistance change per volt applied to the sample. We obtained domain images of freshly cleaved triglycine sulfate (TGS) single crystal by contact mode SRPM. The operating voltage of the probe was 4 V and the scan rate and size were 2 Hz and 40×40 μm2, respectively. We controlled the polarization of Pb(Zr0.4Ti0.6)O3 (PZT) by applying voltage between the resistive tip and the bottom electrode of PZT, and acquired the domain images with the same tip at 2 Hz scan rate. By controlling and dete...

Scanning resistive probe microscopy: Imaging ferroelectric domains

A depth sensor includes a light source, a detector, and a signal processor. The light source transmits a source signal to the target according to a transmit control signal having reference time points. The detector receives a reflected signal from the source signal being reflected from the target. The signal processor generates a plurality of sensed values by measuring respective portions of the reflected signal during respective time periods with different time delays from the reference time points. The signal processor determines a respective delay time for a maximum/minimum of the sensed values for determining the distance of the target.

Three dimensional image sensor

Disclosed is an image sensor capable of improving the resolution of images without modifying the resolution of a photoelectric conversion semiconductor device for sensing images and an image sensing method using the same. The image sensor is adapted to sense images through photoelectric conversion and includes a scanner unit adapted to move on a plane; a photoelectric conversion semiconductor device fixedly mounted on the scanner unit and having a number of pixels being arranged on a front surface; and an array of color filters arranged on the photoelectric conversion semiconductor device so as to correspond to the pixels. The image sensor improves the resolution of sensed images by sensing data of images, which cannot be sensed according to the related art, while using a conventional photoelectric conversion semiconductor device without modification, and without incurring further cost or degrading the performance.

Image sensor and image sensing method using the same

Nanoscale manipulation of surface charges and their imaging are essential for understanding local electronic behaviors of polar materials and advanced electronic devices. Electrostatic force microscopy and Kelvin probe force microscopy have been extensively used to probe and image local surface charges responsible for electrodynamics and transport phenomena. However, they rely on the weak electric force modulation of cantilever that limits both spatial and temporal resolutions. Here we present a field effect transistor embedded probe that can directly image surface charges on a length scale of 25 nm and a time scale of less than 125 μs. On the basis of the calculation of net surface charges in a 25 nm diameter ferroelectric domain, we could estimate the charge density resolution to be as low as 0.08 μC/cm2, which is equivalent to 1/20 electron per nanometer square at room temperature.

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High-resolution field effect sensing of ferroelectric charges.

An image sensor according to an example embodiment concepts includes a pixel array including pixels, and each of the pixels includes photoelectric conversion elements. The photoelectric conversion elements independently operating to detect a phase difference. The image sensor further includes a control circuit configured to independently control exposure times of each of the photoelectric conversion elements included in each of the pixels.

Dong-ki Min

Papers

Scanning resistive probe microscopy: Imaging ferroelectric domains

Three dimensional image sensor

Image sensor and image sensing method using the same

High-resolution field effect sensing of ferroelectric charges.

Image sensor including a pixel having photoelectric conversion elements and image processing device having the image sensor