SCANNING TUNNELING MICROSCOPE
    1.
    发明专利

    公开(公告)号:CA1252918A

    公开(公告)日:1989-04-18

    申请号:CA499457

    申请日:1986-01-13

    Applicant: IBM

    Abstract: Scanning Tunneling Microscope This scanning tunneling microscope consists of a semiconductor chip (7) into which slots are etched to form a central portion (1) linked by a first pair of stripes (2, 3) to an intermediate portion (4) which in turn is linked by a second pair of stripes (5, 6) to the main body of the chip (7). The pairs of stripes (2, 3; 5, 6) have mutually orthogonal directions to allow the center portion (1) to perform movements in x- and y-direc-tions under the control of electrostatic forces created between the stripes (2, 3; 5, 6) and their opposite walls. The center portion (1) has formed into it at least one tongue (17) carrying an integrated, protuding tunnel tip (18) which is capable of being moved in z-direction by means of electrostatic forces between said tongue (17) and the bottom of a cavity below the tongue (17).

    NEAR-FIELD OPTICAL MICROSCOPE
    2.
    发明专利

    公开(公告)号:CA2170860A1

    公开(公告)日:1995-04-13

    申请号:CA2170860

    申请日:1993-10-04

    Applicant: IBM

    Abstract: The invention relates to a near-field optical microscope, in particular to a scanning near-field optical microscope (SNOM), comprising means for determining the intensity of light emerging from the near-field at a direction differing from the direction perpendicular to the surface of the sample to be examined, preferably emerging at an angle .theta. larger than the critical angle. Superposing light with different azimuth angles ? by using suitable positioned mirrors and beamsplitters enables imaging with higher contrast. The invention allows an accurate control of the distance between the probing tip of the SNOM and the sample by using the measured intensity in a feedback loop.

    DIRECT ACCESS STORAGE UNIT
    5.
    发明专利

    公开(公告)号:CA1283733C

    公开(公告)日:1991-04-30

    申请号:CA534217

    申请日:1987-04-08

    Applicant: IBM

    Abstract: Direct Access Storage Unit The storage unit comprises an array of tunnel tips (13) arranged at tunneling distance from a storage medium (2) which is capable of permitting digital information to be written or read through variations of the tunneling current. Each tunnel tip (13) is supported on its own cantilever beam (12) extending across a cavity (14) formed in a common substrate (15). Each cantilever beam (12) as well as the bottom of each cavity (14) are covered with an electrically conducting layer (16, 18) enabling the distance between each one of the tunnel tips (13) and the surface of the storage medium (2) to be electrostatically controlled. The storage medium (2) is attached to the free end of a piezoceramic bender, the end in operation performing a circular motion so that each tunnel tip (13) scans its associated area of the storage medium (2) along a circular track.

    ATOMIC FORCE SENSOR HEAD
    6.
    发明专利

    公开(公告)号:CA1308574C

    公开(公告)日:1992-10-13

    申请号:CA565614

    申请日:1988-04-29

    Applicant: IBM

    Abstract: SZ 9-86-004 The atomic force sensor head comprises a cantilever beam (50) forming an integral part of a body (53) from which it extends such that it has a free end to carry a member (55) for interaction with a surface to be investigated. As said member (55) is brought close to said surface, atomic forces will cause a deflection of said cantilever (50). This deflection is translated into a variation of an electrical value, such as a capacitance. A capacitor (57) is formed by a pairof electrodes (51, 52) coated onto the cantilever beam (50) and said body (53), respectively. The deflection of said cantilever beam (50) causes a variation of the distance (s) between said electrodes (51, 52) and, hence, of the capacitance. An improvement of the sensitivity and stability of this arrangement is made possible by filling the gap between the said electrodes (51, 52) with materials (54, 56) having different dielectric constants and different thicknesses. With arelation of 1:10 of the dielectric constants and a thickness relation of 1:5, animprovement factor of about 40 can be obtained.

    METHOD AND APPARATUS FOR CONTROLLING THE FLYING HEIGHT OF THE HEAD IN A MAGNETIC STORAGE UNIT

    公开(公告)号:CA1290054C

    公开(公告)日:1991-10-01

    申请号:CA519019

    申请日:1986-09-24

    Applicant: IBM

    Abstract: SZ 9-85-01C Method and Apparatus for Controlling the Flying Height of the Head in a Magnetic Storage Unit The method involves the steps of lowering the magnetic head (8) to within aerodynamic distance from the surface (16) of a moving recording medium, enforced further lowering of the head (8) until a tunnel current occurs across the gap between head (8) and surface (16), and maintaining said tunnel current constant by using the deviations of the current from a predetermined value (which corresponds to a certain flying height). The apparatus comprises a tunnel electrode (9) forming an integral part of the head assembly which is attached to a distance control mechanism (5) permitting the positioning of the head assembly with a one-nanometer accuracy. The tunnel electrode (9) has a very slightly beveled shoulder (45, 47) ensuring early detection of asperities approaching the head while sitting on the surface (16) of the moving recording medium (3). Gradation of the potential between tunnel electrode (9) and surface (16) of the recording medium (3) is used to enhance the response to asperities.

    DISTANCE-CONTROLLED TUNNELING TRANSDUCER AND DIRECT ACCESS STORAGE UNIT EMPLOYING THE TRANSDUCER

    公开(公告)号:CA1332761C

    公开(公告)日:1994-10-25

    申请号:CA613500

    申请日:1989-09-27

    Applicant: IBM

    Abstract: This distance-controlled tunneling transducer (1) comprises a plurality of sharply pointed tips (2) arranged in an array at tunneling distance from the electrically conductive surface (6) of a storage medium (7). Each tip (2) is attached to a cantilever beam (3) permitting the distance between each tip (2) and the surface (6) to be individually pre-adjusted by electrostatic means (8, 9). Arranged in juxtaposition with each cantilever beam (3) is a simple active control circuit (12, 13, 16) for adjusting the tip/surface distance during operation of the storage unit thus preventing crashes of the associated tip (2) into possible asperities on the surface (6) of the recording medium (7). Each control circuit (12, 13, 16) is designed such that its operating voltage, at thesame time, serves to pre-adjust its associated cantilever beam (3) and to maintain the gap width essentially constant.

    OSCILLATING QUARTZ ATOMIC FORCE MICROSCOPE

    公开(公告)号:CA1330452C

    公开(公告)日:1994-06-28

    申请号:CA565615

    申请日:1988-04-29

    Applicant: IBM

    Inventor: POHL WOLFGANG D

    Abstract: This atomic force microscope comprises a pointed tip (1) mounted on top of an oscillating crystal (2) which is translatable In xyz-directions by a conventional xyz-drive (4). A potential applied to a pair of electrodes (5, 6) coated on opposite faces of said crystal (2) causes the latter to oscillate with its resonance frequency. As the tip (1) is approached to a surface to be investigated, the frequency of oscillation of the crystal deviates from its original frequency. This deviation can be used in a feedback loop to control thedistance in z-direction of the tip (1) from the surface being investigated and to plot an image of the contour of each scan performed by the tip (1) across the surface.

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