EP0449221A2
Expired / Lapsed
EP
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Scanning probe microscope
Assignee: Olympus Corp
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Filing: 1991-03-26
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Granted: —
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Expires: 2011-03-26
Abstract
Abstract A scanning probe microscope comprises a cantilever (7) having a conductive probe (7a) positioned near a sample (1), an actuator (2) for moving the sample to and away the probe, a circuit (3) for applying a bias voltage between the probe and sample to produce a tunnel current therebetween, a circuit (8) for detecting the produced tunnel current, a circuit (9) for detecting the amount of displacement of the probe resultant from interatomic forces acting between atomics of the probe and sample, thereby producing signals, a circuit (11) for providing the actuator for feedback in response to the output signals from the circuit (9) to retain constant the distance between the probe and sample, thereby causing the actuator to move the sample, a circuit (14) for forming an STS image data from the detected tunnel current a circuit (15) for forming an STM image data from the detected tunnel current, and a circuit (11) for forming an AFM image data. Thus, the STS, STP and AFM images are separately obtained simultaneously.
Inventors
- 👤 Takao Okada
- 👤 Akira Yagi
- 👤 Yasuhiro Sugawara
- 👤 Seizo Morita
- 👤 Tsugiko Takase
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 04:12
CPC Classifications
G; G01; G01Q; G01Q10/00; G01Q10/04; G01Q10/06; G01Q10/065; G01Q20/00; G01Q20/02; G01Q60/00; G01Q60/02; G01Q60/04; G01Q60/10; G01Q60/12; G01Q60/14
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
290 words
A scanning probe microscope comprising: a cantilever (7) including a conductive probe (7a) having a tip portion positioned near the surface of a sample, means (2) for conveying said sample to and away from the tip portion of the probe, means (3, 5, 6) for applying a bias voltage between said probe and sample to produce a tunnel current there-between, means (8) for detecting the produced tunnel current, means (9, 10) for detecting the amount of displacement of the probe resultant from interatomic forces acting between atomics of the tip portion of said probe and of the surface of the sample, thereby producing corresponding signals, a servocontrol means (11) for providing said conveyor means for feedback in response to the output signals from the probe displacement detection means to retain constant the distance between the tip portion of the probe and sample, thereby causing said conveyor means to convey the sample, means (14, 16, 30) for forming a first three-dimensional image (STS image) data of information relative to the local electron state in the surface of the sample which information has been obtained from the tunnel current detected by said tunnel current detection means, means (15, 17, 30, 70, 70a, 71) for forming a second three-dimensional image (STP image) data of information relative to the potential distribution in the surface of the sample, which information has been obtained from the tunnel current detected by said tunnel current detection means, and means (11, 13) for forming a third three-dimensional image (AFM image) data of information about the roughness of the sample surface corresponding to the amount of displacement of the probe detected by said probe displacement detection means, so that said STS, STP and AFM images can be separately obtained simultaneously.
Claim 2
Dependent Claim
77 words
A scanning probe microscope as defined in claim 1, characterized in that said bias voltage impression means (3, 5, 6) includes a modulated voltage generator means for applying between the probe and sample a modulated voltage having a determined cycle and amplitude as a bias voltage, and said means for forming STS image data an arithmetic mean (14) for outputting differential conductances of the tunnel current detected by said tunnel current detection means and said modulated voltage.
Claim 3
Dependent Claim
54 words
A scanning probe microscope as defined in claim 2, characterized in that said STP image data forming means includes a potential servo means (15) for producing a voltage adapted to shift the potential of the bias voltage applied to the sample by integrating the tunnel current detected by said tunnel current flow detection means.
Claim 4
Dependent Claim
134 words
A scanning probe microscope according to claim 1, characterized in that said cantilever has one plane on which said probe is mounted, another plane, and a conductive film (7c) attached to the another plane, said probe displacement detection means comprises a tunnel tip (2) provided near the conductive film of said cantilever, an auxiliary bias voltage applying means (21c) for applying a bias voltage between the tunnel tip and the conductive film to produce a tunnel current flow between the same members, and an auxiliary tunnel current detection means (21) for detecting the tunnel current flow produced by the bias voltage applied by said auxiliary bias voltage impression means, so that the amount of said probe may be detected in accordance with the tunnel current detected by the auxiliary tunnel current detection means (21).
Claim 5
Dependent Claim
71 words
A scanning probe microscope as defined in claim 4, characterized in that said cantilever includes a plate-like electrically insulated member (7b) having one plane and another plane, a conductive member for connection of said probe and said auxiliary tunnel current detection means in case said probe is provided on this one plane and said conductive film is provided on this another plane, and means for connecting said conductive film to earth.
Claim 6
Dependent Claim
52 words
A scanning probe microscope as defined in claim 5, which comprises a logarithm arithmetic means (24) for finding the tunnel current flow detected by said auxiliary tunnel current detection means and the distance between the tunnel tip and conductive film exponentially to produce a signal proportional to the displacement of the cantilever.
Claim 7
Dependent Claim
54 words
A scanning probe microscope as defined in claim 1, characterized in that said STS image data forming means and STP image forming means are constituted by an arithmetic means (30) for performing a digital arithmetic process on the tunnel current detected by the tunnel current detection means to produce STS and STP image data.
Claim 8
Dependent Claim
88 words
A scanning probe microscope as defined in claim 1, characterized in that it comprises an auxiliary servo control means (70) for providing said conveyor means for feedback in response to the tunnel current detected by said tunnel current detection means so as to retain constant the distance between the probe and sample, thereby causing said conveyor means to convey the sample, and a connection switching means (71) for executing selective connections of the auxiliary servo control means (70) and said servo control means (11) with said conveyor means.
Claim 9
Dependent Claim
116 words
A microscope having a multi-function scanning probe, comprising: stimulus-applying means for externally applying various stimuli to a sample; first detection means for detecting a first physical quantity which varies with the stimuli applied to the sample from said stimulus-applying means; second detection means for detecting a second physical quantity which varies with the stimuli applied to the sample from said stimulus-applying means; servo means for controlling a distance between the probe and the sample such that a signal output by said second detection means is maintained at a constant value; and recording means for recording signals output by said first and second detection means and the various stimuli applied to the sample from said stimulus-applying means.
Claim 10
Dependent Claim
50 words
The microscope according to claim 9, further comprising second servo means for controlling a distance between the probe and the sample such that a signal output by said first detection means is maintained at a constant value; and switching means for selecting said servo means or said second servo means.
Claim 11
Dependent Claim
43 words
The microscope according to claim 9, characterized in that said stimulus-applying means is means for changing a tunnel bias voltage applied to the sample, and said first physical quantity is a change in a tunnel current flowing between the probe and the sample.
Claim 12
Dependent Claim
35 words
The microscope according to claim 9, characterized in that said stimulus-applying means is means for applying light to the sample, thereby to excite the sample optically, and said first physical quantity is a light-excited current.
Claim 13
Dependent Claim
33 words
The microscope according to claim 9, characterized in that said stimulus-applying means is means for changing heat to a specified portion of the sample, and said first physical quantity is a heat-excited current.
Claim 14
Dependent Claim
44 words
The microscope according to claim 9, characterized in that said stimulus-applying means is means for applying light beams having various wavelengths, and said first physical quantity is an amount heat which the sample generates in response to a light beam having a specified wavelength.
Claim 15
Dependent Claim
44 words
The microscope according to claim 9, characterized in that said stimulus-applying means is means for applying metal colloid to the sample, and said first physical quantity is a change in a tunnel current which is caused by the metal colloid existing on the sample.
References Cited (Backward Citations)
No citation records indexed.
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