公开(公告)号：DE69003047D1

公开(公告)日：1993-10-07

申请号：DE69003047

申请日：1990-06-19

Applicant: IBM

Inventor： ABRAHAM DAVID W ,  WICKRAMASINGHE HEMANTHA K

IPC: G01R33/028 ,  G01B7/34 ,  G01N27/00 ,  G01N27/82 ,  G01Q10/00 ,  G01Q20/02 ,  G01Q30/02 ,  G01Q30/04 ,  G01Q30/18 ,  G01Q60/10 ,  G01R33/10 ,  G01R33/12 ,  G01L5/00

Abstract: Magnetic structures of a sample (46) are imaged by measuring Lorentz force-induced deflection of the tip (40) of a scanning tunneling microscope. While scanning the sample (46), an a.c. voltage signal at a first predetermined frequency equal to the resonance frequency of the tip (40) is applied to the tip (40) for generating a current between the tip (40) and the surface (44) of the sample (46) for causing the tip (40) to undergo vibratory motion relative to the sample (46). The tip (40) motion, indicative of the presence of a magnetic field, is optically detected. In an alternative embodiment for providing improved resolution the tip (40) is made to undergo motion at a second predetermined frequency in a direction parallel to the longitudinal axis of the tip (40) and normal to the surface (44) of the sample (46). The tip (40) motion is optically detected at the sum or difference frequency of the first and second predetermined frequencies for providing improved lateral resolution of the magnetic field measurements using a scanning tunneling microscope. In the alternative embodiment the sum or difference frequency, which ever is detected, is made equal to the resonance frequency of the tip (40). The magnetic field measurement and tip (40) position are provided to a computer (68) which, in turn, provides an output signal to a device (72) for providing a graphical representation of the magnetic field at different positions on the surface (44) of the sample (46).

公开(公告)号：DE69003047T2

公开(公告)日：1994-04-21

申请号：DE69003047

申请日：1990-06-19

Applicant: IBM

Inventor： ABRAHAM DAVID W ,  WICKRAMASINGHE HEMANTHA K

IPC: G01R33/028 ,  G01B7/34 ,  G01N27/00 ,  G01N27/82 ,  G01Q10/00 ,  G01Q20/02 ,  G01Q30/02 ,  G01Q30/04 ,  G01Q30/18 ,  G01Q60/10 ,  G01R33/10 ,  G01R33/12 ,  G01L5/00

Abstract: Magnetic structures of a sample (46) are imaged by measuring Lorentz force-induced deflection of the tip (40) of a scanning tunneling microscope. While scanning the sample (46), an a.c. voltage signal at a first predetermined frequency equal to the resonance frequency of the tip (40) is applied to the tip (40) for generating a current between the tip (40) and the surface (44) of the sample (46) for causing the tip (40) to undergo vibratory motion relative to the sample (46). The tip (40) motion, indicative of the presence of a magnetic field, is optically detected. In an alternative embodiment for providing improved resolution the tip (40) is made to undergo motion at a second predetermined frequency in a direction parallel to the longitudinal axis of the tip (40) and normal to the surface (44) of the sample (46). The tip (40) motion is optically detected at the sum or difference frequency of the first and second predetermined frequencies for providing improved lateral resolution of the magnetic field measurements using a scanning tunneling microscope. In the alternative embodiment the sum or difference frequency, which ever is detected, is made equal to the resonance frequency of the tip (40). The magnetic field measurement and tip (40) position are provided to a computer (68) which, in turn, provides an output signal to a device (72) for providing a graphical representation of the magnetic field at different positions on the surface (44) of the sample (46).

公开(公告)号：CA2107048A1

公开(公告)日：1994-05-10

申请号：CA2107048

申请日：1993-09-27

Applicant: IBM

Inventor： ABRAHAM DAVID W ,  HAMMOND JAMES M ,  KLOS MARTIN A ,  ROESSLER KENNETH G ,  STOWELL ROBERT M ,  WICKRAMASINGHE HEMANTHA K

IPC: G01B7/34 ,  G01B21/30 ,  G01Q70/04 ,  H01J37/20 ,  H01J37/28 ,  G02B21/26

公开(公告)号：DE69019412T2

公开(公告)日：1996-01-25

申请号：DE69019412

申请日：1990-02-12

Applicant: IBM

Inventor： WICKRAMASINGHE HEMANTHA K

IPC: G01N25/00 ,  G01B7/02 ,  G01K1/16 ,  G01N1/28 ,  G01N21/00 ,  G01N27/00 ,  G01N37/00 ,  G01Q30/10 ,  G01Q60/12 ,  H01J37/28

Abstract: High resolution absorption microscopy, spectroscopy and similar applications are implemented by providing for a measurement tip (21) which is maintained spaced from a sample (10) under investigation sufficiently close so as to equalize thermal levels in the tip (21) and the sample (10); generally within about 1 nm. Energy is applied to the sample (10) being investigated and either a steady state or dynamic junction potential is measured. The close separation can be maintained by techniques employed in scanning tunneling microscopy, atomic force microscopy or capacitance microscopy. In the event the close separation is maintained using scanning tunneling microscopy techniques, then a switching arrangement (30) is provided for connecting a conductive film (11) (either of the sample (10) or supported on a sample (10)) to either a suitable potential or ground and simultaneously connecting the STM tip (21) either in a feedback loop or to a device for measuring the junction potential. The feedback loop, in addition to conventional operational amplifier components, includes a sample and hold element (55) to maintain the input voltage to an operational amplifier (23) in the feedback loop during those times that the measurement tip (21) is connected to the junction potential measurement device, as opposed to being connected in the STM feedback loop. The spectroscopy application uses similar architecture, although the energy source (15) is tunable.

公开(公告)号：DE69019412D1

公开(公告)日：1995-06-22

申请号：DE69019412

申请日：1990-02-12

Applicant: IBM

Inventor： WICKRAMASINGHE HEMANTHA K

IPC: G01N25/00 ,  G01B7/02 ,  G01K1/16 ,  G01N1/28 ,  G01N21/00 ,  G01N27/00 ,  G01N37/00 ,  G01Q30/10 ,  G01Q60/12 ,  H01J37/28

Abstract: High resolution absorption microscopy, spectroscopy and similar applications are implemented by providing for a measurement tip (21) which is maintained spaced from a sample (10) under investigation sufficiently close so as to equalize thermal levels in the tip (21) and the sample (10); generally within about 1 nm. Energy is applied to the sample (10) being investigated and either a steady state or dynamic junction potential is measured. The close separation can be maintained by techniques employed in scanning tunneling microscopy, atomic force microscopy or capacitance microscopy. In the event the close separation is maintained using scanning tunneling microscopy techniques, then a switching arrangement (30) is provided for connecting a conductive film (11) (either of the sample (10) or supported on a sample (10)) to either a suitable potential or ground and simultaneously connecting the STM tip (21) either in a feedback loop or to a device for measuring the junction potential. The feedback loop, in addition to conventional operational amplifier components, includes a sample and hold element (55) to maintain the input voltage to an operational amplifier (23) in the feedback loop during those times that the measurement tip (21) is connected to the junction potential measurement device, as opposed to being connected in the STM feedback loop. The spectroscopy application uses similar architecture, although the energy source (15) is tunable.

公开(公告)号：DE69009846T2

公开(公告)日：1995-01-05

申请号：DE69009846

申请日：1990-03-21

Applicant: IBM

Inventor： WICKRAMASINGHE HEMANTHA K ,  WILLIAMS CLAYTON C

IPC: G02B21/36 ,  G01B11/30 ,  G01N37/00 ,  G01Q20/02 ,  G01Q60/22 ,  G02B21/00

Abstract: A near field optical microscopy method and apparatus eliminates the necessity of an aperture for scanning a sample surface (18) and greatly reduces the detected background signal. A small dimension tip (14), on the order of atomic dimension, is disposed in close promity to the sample surface (18). A dither motion is applied to the tip (14) at a first frequency in a direction substantially normal (22) to the plane of the sample surface (18). Dither motion is simultaneously applied to the sample (20) at a second frequency in a direction substantially parallel (24) to the plane of the sample surface (18). The amplitude of the motions are chosen to be comparable to the desired measurement resolution. The end (12) of the tip (14) is illuminated by optical energy. The scattered light from the tip (14) and surface (18) is detected at the difference frequency for imaging the sample surface (18) at sub-wavelength resolution without the use of an aperture. Alternatively, the tip (14) is maintained stationary and the sample (20) undergoes motion in the two directions.

公开(公告)号：DE69009846D1

公开(公告)日：1994-07-21

申请号：DE69009846

申请日：1990-03-21

Applicant: IBM

Inventor： WICKRAMASINGHE HEMANTHA K ,  WILLIAMS CLAYTON C

IPC: G02B21/36 ,  G01B11/30 ,  G01N37/00 ,  G01Q20/02 ,  G01Q60/22 ,  G02B21/00

Abstract: A near field optical microscopy method and apparatus eliminates the necessity of an aperture for scanning a sample surface (18) and greatly reduces the detected background signal. A small dimension tip (14), on the order of atomic dimension, is disposed in close promity to the sample surface (18). A dither motion is applied to the tip (14) at a first frequency in a direction substantially normal (22) to the plane of the sample surface (18). Dither motion is simultaneously applied to the sample (20) at a second frequency in a direction substantially parallel (24) to the plane of the sample surface (18). The amplitude of the motions are chosen to be comparable to the desired measurement resolution. The end (12) of the tip (14) is illuminated by optical energy. The scattered light from the tip (14) and surface (18) is detected at the difference frequency for imaging the sample surface (18) at sub-wavelength resolution without the use of an aperture. Alternatively, the tip (14) is maintained stationary and the sample (20) undergoes motion in the two directions.