International Business Machines Corporation

Other

Headway Technologies, Incorporated

Magic Technologies, Inc.

Otto Voegeli

Peter Vettiger

Mohamad Towfik Krounbi

Po-Kang Wang

Peter L Buchmann

David J Webb

George Tzanavaras

Peter Unger

Kochan Ju

Cherng-Chyi Han

Tai Min

Rongfu Xiao

Youfeng Zheng

John Casimir Slonczewski

John Scott Eggenberger

Kay Beharat Mehta

Joost Mortelmans

Rajendra Rangraj Mehta

Shiezen Huang

Bertram A Calhoun

A magnetic sensor for identifying small magnetic particles bound to a substrate includes a regular, planar orthogonal array of MTJ cells formed within or beneath that substrate. Each MTJ cell has a high aspect ratio and positions of stable magnetic equilibrium along an easy magnetic axis and positions of unstable magnetic equilibrium along a hard magnetic axis. By initializing the magnetizations of each MTJ cell in its unstable hard-axis position, the presence of even a small magnetic particle can exert a sufficient perturbative strayfield to tip the magnetization to its stable position. The magnetization change in an MTJ cell can be measured after each of two successive opposite polarity magnetizations of a bound particle and the presence of the particle thereby detected.

Bio-sensor with hard-direction field

A system and method of generating a magnetic field that is uniform in magnitude and direction may generally restrict the field from expanding away from a longitudinal axis. In some instances, such a magnetic field may be controllable in magnitude and direction. In accordance with some embodiments, a generated magnetic field may be selectively confined to a predetermined three-dimensional space.

Confined field magnet system and method

A planar array of GMR or TMR sensor elements with planar free and pinned layers is used as the basis of a sensor for detecting the presence of small magnetized particles. In particular, the sensor is used for detecting the presence of magnetized particles bonded to biological molecules that are themselves bonded to a substrate. The magnetized particles on the molecules are detected by the sensors as a result of the interaction between the stray fields of the particles and the magnetic configuration of the sensors. By forming a co-planar layer of soft magnetic material over the sensor or its array, the external field used to magnetize the particles is self-aligned perpendicularly to the sensor plane whereby it does not interfere with the stray fields of the particles.

GMR biosensor with aligned magnetic field

A method of fabricating a current-perpendicular-to-plane (CPP) giant magnetoresistive (GMR) sensor stack, wherein the parasitic resistance of the high-resistance antiferromagnetic (AFM) pinning layer is effectively reduced by enlarging its surface area and forming between it and the remainder of the sensor stack an equal area, contiguous, thin, highly conductive ferromagnetic layer, the current channeling (CCL) layer. The magnetic properties and increased current carrying capacity of the CCL allows the AFM pinning layer to effectively couple to the pinned layer while eliminating the effect of its high resistance on the sensor sensitivity as measured by the GMR ratio, &#x394;R/R.

Process of making a GMR improvement in CPP spin valve head by inserting a current channeling layer (CCL)

A magnetic shielding element for a magnetic recording and sensing device which prevents the problem of pop-corn noise or covariance of amplitude noise in the magnetic sensing device. The shielding element has a layer of antiferromagnetic exchange material formed on a layer of single domain first ferromagnetic material. The single domain first ferromagnetic material is stabilized by the antiferromagnetic exchange material. A layer of non-magnetic metal is then formed on the layer of antiferromagnetic exchange material and a layer of second ferromagnetic material is formed on the layer of non-magnetic metal to complete the shielding element. When the single domains of the first ferromagnetic material are disturbed by the strong magnetic fields of a write cycle they relax with a relaxation time of pico seconds and are fully relaxed before a read cycle begins. The fully relaxed layer of first ferromagnetic material then shields the magnetic sensing device from magnetic field fluctuations caused by the slower relaxation of the domains in the layer of second ferromagnetic material during a read cycle.

Magnetic recording sensor with stabilizing shield

A magnetoresistive transducer has a sensor which includes a magnetic layer and an interdiffusion layer. An active central region of the sensor extends between two passive end regions which are used to magnetically bias the active central region longitudinally. The biasing function is attained by fabricating the transducer on a wafer in an H-configuration, with the crossbar of the H as the active central region and a portion of the side legs as the passive end regions. When short current pulses are passed through the side legs of the H, the associated heating of the side legs (but not the crossbar of the H) causes interdiffusion between the interdiffusion layer and the magnetic layer and transforms the magnetic layer from soft magnetism to hard magnetism as required for the biasing function. The wafer is diced near the crossbar of the H and then processed further to form the finished transducer.

Method of fabricating magnetoresistive transducer

A thin film magnetic structure for use as a flux guide in a magnetic recording system has tapered edges transverse to the magnetization axis of the film. The tapered edges eliminate magnetic edge domains and thereby assure a single magnetic domain in the film structure. Thus, Barkhausen noise is essentially eliminated from the signal read by the film structure from the magnetic recording medium.

Thin film magnetic head structure having tapered side edges

Magnetoresistive transducer including interdiffusion layer

Cooling structure for direct heat transfer between an active layer of a chip in which electric elements are formed and a heat sink are disclosed. The inventive cooling structure consists of a current/voltage supply level, with metal structures and insulation spacers and/or layers, partly covered by an insulation layer and followed by a heat transfer structure. A heat transfer bridge is in thermal connection with the heat transfer structure that provides for heat flux between the inventive cooling structure and the heat sink. The inventive cooling structure of this invention can be used with semiconductor devices and/or with opto-electronic devices.

Method for making cooling structures for directly cooling an active

An integrated light deflector and fabrication method are disclosed. In accordance with the method, a mold is constructed above the surface of a substrate using a thick photo resist and a mask to define a deflector plane. A collimated light beam is applied at an appropriate angle of incidence to the photo resist material and mask. The developed resist provides a mold into which the deflector body is cast, leaving a deflector body whose front surface serves as the deflecting surface.

Integrated light deflector and method of fabrication therefor

Cooling structures and package modules for semiconductors

A magnetoresistive (MR) read transducer comprising an MR layer having longitudinally magnetized end regions separated by a central active region and a soft magnetic biasing layer parallel to but spaced from the MR layer. The easy axes of the MR layer and the soft magnetic biasing layer are tilted at a small angle with respect to the longitudinal axis of the transducer and these angles are substantially equal, but in the opposite sense.

Anisotropy configuration for longitudinally constrained magnetoresistive

A method, and device produced therewith, for improving the planarity of etched mirror facets 18 of integrated optic structures with non-planar stripe waveguides, such as ridge or groove diode lasers or passive devices such as modulators and switches. The curvature of the mirror facet surface at the edges of the waveguide due to topographical, lithographical and etch process effects, causes detrimental phase distortions, and is avoided by widening the waveguide end near the mirror surface thereby shifting the curved facet regions away from the light mode region to surface regions where curvature is not critical.

Growing community of inventors

Morgan Hill, CA, United States of America

Otto Voegeli