Double cantilever sensor for atomic force microscope
First Claim
1. An atomic force microscope for performing atomic force and surface potential measurements on a sample, the combination comprising:
- a conductive probe beam including two segments, a first segment exhibiting a mechanical fundamental resonant frequency of f1 and a second segment exhibiting a mechanical fundamental resonant frequency of f2 ;
actuator means mechanically coupled to said probe beam for oscillating said probe beam at said f1 frequency;
oscillator means electrically connected to said probe beam for applying a signal of frequency f2 thereto;
means for inducing relative movement between said sample and said probe beam in a direction that is transverse to a surface of said sample; and
means for sensing movements of said probe beam that are orthogonal to the surface of said sample and for providing an output signal indicative of movement of said second segment of said probe beam at said f2 frequency.
1 Assignment
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Accused Products
Abstract
An atomic force microscope that performs both atomic force and surface potential measurements on a sample comprises a conductive probe beam that includes two segments, a first segment exhibiting a first mechanical resonant frequency and a second segment exhibiting a second different mechanical resonant frequency. An actuator causes oscillations in the probe beam at the first mechanical resonant frequency. An oscillator applies to the probe beam a signal having a frequency equal to the second mechanical resonant frequency. Due to the potential difference between the probe beam and the sample, a force results that causes the probe beam to vibrate. The probe beam is moved over the sample'"'"'s surface in a direction parallel to the surface. An optical heterodyne system senses movements of the probe beam at both the first and second resonant frequencies and provides an output signal indicative of the second resonant frequency movement of the probe beam'"'"'s second segment. In a further embodiment, second and third harmonics of the second resonant frequency are applied to the probe beam and enable the measurement of capacitance changes between the probe beam and the sample surface and changes in capacitance with respect to voltage over the sample'"'"' s surface.
160 Citations
12 Claims
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1. An atomic force microscope for performing atomic force and surface potential measurements on a sample, the combination comprising:
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a conductive probe beam including two segments, a first segment exhibiting a mechanical fundamental resonant frequency of f1 and a second segment exhibiting a mechanical fundamental resonant frequency of f2 ; actuator means mechanically coupled to said probe beam for oscillating said probe beam at said f1 frequency; oscillator means electrically connected to said probe beam for applying a signal of frequency f2 thereto; means for inducing relative movement between said sample and said probe beam in a direction that is transverse to a surface of said sample; and means for sensing movements of said probe beam that are orthogonal to the surface of said sample and for providing an output signal indicative of movement of said second segment of said probe beam at said f2 frequency. - View Dependent Claims (2, 3, 4, 5)
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6. An atomic force microscope for determining characteristics of a sample, comprising:
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a conductive probe beam including first and second segments, said first segment exhibiting a mechanical fundamental resonant frequency at f1 and said second segment exhibiting a mechanical fundamental resonant frequency at f2, f2 being greater than f1 ; actuator means mechanically coupled to said probe beam for oscillating said probe beam at said f1 frequency; oscillator means connected to said probe beam for applying an AC signal thereto, said AC signal having a component frequency of said f2 frequency; and interferometric means for sensing movements of said second segment of said probe beam and for providing an output indicative of movements of said second segment at said f2 frequency. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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Specification