PROBE DETECTION SYSTEM
First Claim
1. A detection system for use with a scanning probe microscope, the system comprising a light source for generating a beam to illuminate a probe comprising a cantilever with base and free ends, the free end supporting a sharp tip, collecting means for collecting light reflected from the probe wherein the beam illuminates an upper surface of the probe in the vicinity of its tip, and the reflected light comprises two components:
- a first component from which an indication of the deflection of the upper surface of the probe is obtained and a second component for transmission to a height detection system arranged to extract from this component information relating to the position of the upper surface of the probe relative to a reference point.
1 Assignment
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Accused Products
Abstract
A probe detection system (74) for use with a scanning probe microscope comprises both a height detection system (88) and deflection detection system (28). As a sample surface is scanned, light reflected from a microscope probe (16) is separated into two components. A first component (84) is analysed by the deflection detection system (28) and is used in a feedback system that maintains the average probe deflection substantially constant during the scan. The second component (86) is analysed by the height detection system (88) from which an indication of the height of the probe above a fixed reference point, and thereby an image of the sample surface, is obtained. Such a dual detection system is particularly suited for use in fast scanning applications in which the feedback system is unable to respond at the rate required to adjust probe height between pixel positions.
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Citations
35 Claims
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1. A detection system for use with a scanning probe microscope, the system comprising a light source for generating a beam to illuminate a probe comprising a cantilever with base and free ends, the free end supporting a sharp tip, collecting means for collecting light reflected from the probe wherein the beam illuminates an upper surface of the probe in the vicinity of its tip, and the reflected light comprises two components:
- a first component from which an indication of the deflection of the upper surface of the probe is obtained and a second component for transmission to a height detection system arranged to extract from this component information relating to the position of the upper surface of the probe relative to a reference point.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 34)
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23. A scanning probe microscope for imaging a sample in accordance with an interaction between the sample and a probe, the microscope comprising driving means arranged to provide relative motion between the probe and the sample surface and a probe detection system arranged to provide an indication of a position of the probe relative to a reference point in a direction substantially perpendicular to the sample surface, wherein
the probe comprises a cantilever with base and free ends, the free end supporting a sharp tip; -
the driving means comprises an xy scanner arranged to provide relative motion between the probe and the sample surface in a plane substantially parallel to the sample surface, the scanner including at least one resonator arranged to oscillate either the probe or sample plus support at or near its resonant frequency, and a z driver arranged to provide relative motion in the direction substantially perpendicular to the sample surface; and the probe detection system comprises a light source for generating a beam to illuminate the probe, collecting means for collecting light reflected from the probe wherein the beam illuminates an upper surface of the probe in the vicinity of its tip, and a height detection system arranged to extract from light reflected from the probe information relating to the position of the upper surface of the probe relative to a reference point. - View Dependent Claims (24)
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- 25. A method of detecting light reflected from an upper surface of a scanning probe, the method including the step of directing a light beam on the upper surface at a point directly above a probe tip, collecting light reflected from the upper surface and directing it to a height detector arranged to form an image indicative of the height of the probe tip above a reference level.
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35. A method of collecting data using a scanning probe microscope, the method comprising the steps of:
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(a) moving a probe comprising a cantilever with base and free ends, the free end supporting a sharp tip, into close proximity with a sample surface; (b) directing a light beam on an upper surface of the probe at a point directly above the tip; and (c) scanning the probe across the sample surface whilst collecting and analysing light reflected from the upper surface of the probe, a z driver being operative to drive the base of the probe vertically in response to a feedback signal obtained by analysis of a first component of the collected light, from which is obtained an indication of the deflection of the upper surface of the probe and wherein a second component of collected light is transmitted to an interferometer arranged to detect the path difference between this component and a height reference beam and arranged to form an image indicative of the height of the probe tip above a reference level.
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Specification