Nec Research Institute, Inc.

Washington University

Other

Nec Corporation

Tdk Corporation

Nec Laboratories America, Inc.

Stuart A Solin

Tineke Thio

Samuel A Wickline

Kirk D Wallace

Michael S Hughes

Richard A Stradling

Tao Zhou

Masaya Kawano

Daniel R Hines

Akm Shah Newaz

James Bennett

Kazuhiko Hayashi

Ronald A Schachar

Keishi Ohashi

Mino Green

Koichi Sassa

Peter A Wolff

Jerrold Widran

Ned Scott Wingreen

John M Sullivan, Jr

Shin Tsuchiya

Alistair C H Rowe

Mark Lee

Gerald T Seidler

Jonathan E Moussa

Lakshminarayanapuram Ramdas Ram-Mohan

Disclosed herein is an apparatus comprising a metal shunt and a semiconductor material in electrical contact with the metal shunt, thereby defining a semiconductor/metal interface for passing a flow of current between the semiconductor material and the metal shunt in response to an application of an electrical bias to the apparatus, wherein the semiconductor material and the metal shunt lie in different planes that are substantially parallel planes, the semiconductor/metal interface thereby being parallel to planes in which the semiconductor material and the metal shunt lie, and wherein, when under the electrical bias, the semiconductor/metal interface is configured to exhibit a change in resistance thereof in response to a perturbation. Such an apparatus can be used as a sensor and deployed as an array of sensors.

Multifunctional nanoscopy for imaging cells

The inventors disclose a new high performance optical sensor, preferably of nanoscale dimensions, that functions at room temperature based on an extraordinary optoconductance (EOC) phenomenon, and preferably an inverse EOC (I-EOC) phenomenon, in a metal-semiconductor hybrid (MSH) structure having a semiconductor/metal interface. Such a design shows efficient photon sensing not exhibited by bare semiconductors. In experimentation with an exemplary embodiment, ultrahigh spatial resolution 4-point optoconductance measurements using Helium-Neon laser radiation reveal a strikingly large optoconductance property, an observed maximum measurement of 9460% EOC, for a 250 nm device. Such an exemplary EOC device also demonstrates specific detectivity higher than 5.06&#xd7;10cm&#x221a;Hz/W for 632 nm illumination and a high dynamic response of 40 dB making such sensors technologically competitive for a wide range of practical applications.

Method and apparatus for high resolution photon detection based on extraordinary optoconductance (EOC) effects

Disclosed herein is an apparatus comprising a metal shunt and a planar semiconductor material in electrical contact with the metal shunt, the metal shunt located on a surface of the semiconductor material, thereby defining a semiconductor/metal interface for passing a flow of current between the semiconductor material and the metal shunt in response to an application of an electrical bias to the apparatus, wherein a portion of that semiconductor material surface is not covered by the metal shunt, wherein the semiconductor material and the metal shunt lie in different planes that are substantially parallel planes, the semiconductor/metal interface thereby being parallel to the plane of semiconductor material, and wherein, when under the electrical bias, the semiconductor/metal interface is configured to exhibit a change in resistance thereof in response to a perturbation. Such an apparatus can be used as a sensor and deployed as an array of sensors.

Disclosed herein is an apparatus for sensing characteristics of an object. In a preferred embodiment, the apparatus comprises an array, wherein the array comprises a plurality of nanoscale hybrid semiconductor/metal devices which are in proximity to an object, each hybrid semiconductor/metal device being configured to produce a voltage in response to a perturbation, wherein the produced voltage is indicative of a characteristic of the object. Any of a variety of nanoscale EXX sensors can be selected as the hybrid semiconductor/metal devices in the array. With such an array, ultra high resolution images of nanoscopic resolution can be generated of objects such as living cells, wherein the images are indicative of a variety of cell biologic processes.

Extraordinary piezoconductance, or change in conductance with strain or pressure, is observed in a hybrid metal-semiconductor device formed from a semiconductor thin film and an adjacent metal shunt fabricated on a semi-insulating substrate. The device includes electrodes for applying a current to the device and for measuring a resulting induced voltage. Strain that is induced in the device, including at the interface between the semiconductor and the metal shunt, changes the resistance at the interface. The device can be used to measure strain or environmental conditions such as pressure or temperature. A sensor using the device includes a frame with a thin membrane on which the device is carried. Deformations in the membrane are transferred to the device to induce strain in the device.

Extraordinary piezoconductance in inhomogeneous semiconductors

This invention relates to a method and system for finite element modeling of enhanced magnetoresistance in thin film semiconductors containing at least one metallic inclusion therein. The method and system utilizes finite element analysis techniques as a function of the applied magnetic field and the geometry of the device for comparing the device characteristics with predetermined qualities and modifying the device to achieve a correlation between the device characteristics and the predetermined qualities.

Method and system for finite element modeling and simulation of enhanced magnetoresistance in thin film semiconductors with metallic inclusions

A magnetoresistive sensor includes a magnetoresistive element and equipment which generates a magnetic field in the magnetoresistive element thereby inducing a biasing magnetic field in the element, where the magnetoresistive element comprises a high electron mobility semiconductor and electrodes which are connected to the semiconductor. If it is an insulator, the equipment, which generates the biasing magnetic field and supplies it to the magnetoresistive element, may contact directly to the magnetoresistive element. If it is a conductor, an insulating separation layer must be set between the equipment and the element. A magnetoresistive element is representatively Corbino disk type or a bar type magnetoresistive element. Another candidate of the magnetoresistive element is an element consisting of a high electron mobility semiconductor, a pair of electrodes which make a current path in the high electron mobility semiconductor, and another pair of electrodes to detect the induced voltage by the current.

Magnetoresistive sensor, magnetoresistive head, and magnetic recording/reproducing apparatus

A symmetric van der Pauw disk of homogeneous nonmagnetic semiconductor material, such as indium antimonide, with an embedded concentric conducting material inhomogeneity, such as gold, exhits room temperature geometric extraordinary magnetoresistance (EMR) as high as 100%, 9,100% and 750,000% at magnetic fields of 0.05, 0.25 and 4.0 Tesla, respectively. Moreover, for inhomogeneities of sufficiently large cross section relative to that of the surrounding semiconductor material, the resistance of the disk is field-independent up to an onset field above which the resistance increases rapidly. These results can be understood in terms of the field-dependent deflection of current around the inhomogeneity. The EMR exhibited by a composite van der Pauw sensor comprising a semiconductor having an embedded metallic inhomogeneity or internal shunt can be obtained from electrically equivalent externally shunted structures, such as rectangular plates including an external conductive shunt element which is simple to manufacture in the mesoscopic sizes required for important magnetic sensor applications. For example, a bilinear conformal mapping is used to transform a circular composite van der Pauw disk sensor having an embedded conducting inhomogeneity into a corresponding externally shunted rectangular plate structure. The result is an EMR sensor that can be realized in very simple structures which facilitate fabrication in mesoscopic dimensions important for many magnetic sensor applications.

Extraordinary magnetoresistance at room temperature in inhomogeneous narrow-gap semiconductors

Mesoscopic magnetic field sensors which can detect weak magnetic fields (typically 0.05 Tesla) over areas as small as tens of thousands of square nanometers (e.g. 40 nm&times;400 nm). The combination of enhanced magneto-resistance in an inhomogeneous high mobility semiconductor, having special electrode arrangements, with the use of island lithography, enables the production of special semiconductor/metal nano-composite structures, and has made possible the fabrication of an entirely new type of magnetic field sensor which exhibits very superior magneto-resistive behavior.

Mesoscopic non-magnetic semiconductor magnetoresistive sensors fabricated with island lithography

Thin, horizontal-plane Hall sensors for read-head in magnetic recordings and methods for fabricating the sensor provide a novel sensor exhibiting high sensitivity and high spatial resolution.

Thin, horizontal-plane hall sensors for read-heads in magnetic recording

Method of making thin, horizontal-plane hall sensors for read-heads in

A self-biasing, non-magnetic giant magnetoresistive sensor having a Corbino-disk geometry constructed from a thin film of e.g., doped, Mercury Cadmium Telluride (MCT) Hg.sub.1-x Cd.sub.x Te exhibiting anomalously large Giant Magnetresistance (GMR) and zero field offset. In one embodiment, the sensor has a silicon substrate, a layer of doped, inhomogeneous MCT, and electrodes attached to the inhomogeneous layer. Alternatively, a buffer layer of, e.g., CdTe may overlay the substrate. In another embodiment, the sensor has a silicon substrate, a layer of doped, homogeneous MCT, and electrodes attached to the doped homogeneous MCT. Alternatively, a buffer layer of, e.g., CdTe may overlay the substrate as well. With constructed in as either of these embodiments, highly doped Corbino devices may show a significant zero-field offset in the GMR which results in a built-in bias field as high as 1500 G at T=300 K.

Self-biasing, non-magnetic, giant magnetoresistance sensor

The low-field magnetoresistance of a high carrier mobility semiconductor with inhomogeneities which are more conducting than the surrounding semiconductor material matrix is significantly enhanced compared to the magnetoresistance of the homogeneous material. The enhancement results from a magnetic field induced geometric effect in which current is expelled from the conducting inhomogeneity. The enhanced giant magnetoresistance is demonstrated at low field in (near) zero-band-gap material, such as Hg.sub.1-x Cd.sub.x Te(x.about.0.1). The effect is applied to the fabrication of magnetic read head sensors such as Corbino disc, bar magnetoresistance sensors and thin film sensors.

GMR enhancement in inhomogeneous semiconductors for use in

A non-magnetic magnetoresistive head for reading a magnetic pattern stored as domains in tracks on a storage device uses as the sensor a wafer of a high electron mobility non-magnetic semiconductor, such as indium antimonide or mercury-cadmium telluride, which includes an electrode configuration that includes an inner stripe electrode and an outer rectangular electrode surrounding the inner electrode. The wafer is supported so that the plane of the wafer is parallel to the disk and perpendicular to the magnetic field being sensed.

Growing community of inventors

St. Louis, MO, United States of America

Stuart A Solin