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Title: Topography imaging with a heated atomic force microscope cantilever in tapping mode

Abstract

This article describes tapping mode atomic force microscopy (AFM) using a heated AFM cantilever. The electrical and thermal responses of the cantilever were investigated while the cantilever oscillated in free space or was in intermittent contact with a surface. The cantilever oscillates at its mechanical resonant frequency, 70.36 kHz, which is much faster than its thermal time constant of 300 {mu}s, and so the cantilever operates in thermal steady state. The thermal impedance between the cantilever heater and the sample was measured through the cantilever temperature signal. Topographical imaging was performed on silicon calibration gratings of height 20 and 100 nm. The obtained topography sensitivity is as high as 200 {mu}V/nm and the resolution is as good as 0.5 nm/Hz{sup 1/2}, depending on the cantilever power. The cantilever heating power ranges 0-7 mW, which corresponds to a temperature range of 25-700 deg. C. The imaging was performed entirely using the cantilever thermal signal and no laser or other optics was required. As in conventional AFM, the tapping mode operation demonstrated here can suppress imaging artifacts and enable imaging of soft samples.

Authors:
; ; ;  [1];  [2]
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  1. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
20953428
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 78; Journal Issue: 4; Other Information: DOI: 10.1063/1.2721422; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ATOMIC FORCE MICROSCOPY; CALIBRATION; DIFFRACTION GRATINGS; GRATINGS; HEATING; POWER RANGE; SEMICONDUCTOR MATERIALS; SIGNALS; SILICON; STEADY-STATE CONDITIONS; SURFACES; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; TOPOGRAPHY

Citation Formats

Park, Keunhan, Lee, Jungchul, Zhang, Zhuomin M., King, William P., and Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801. Topography imaging with a heated atomic force microscope cantilever in tapping mode. United States: N. p., 2007. Web. doi:10.1063/1.2721422.
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Park, Keunhan, Lee, Jungchul, Zhang, Zhuomin M., King, William P., & Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801. Topography imaging with a heated atomic force microscope cantilever in tapping mode. United States. doi:10.1063/1.2721422.
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Park, Keunhan, Lee, Jungchul, Zhang, Zhuomin M., King, William P., and Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801. Sun . "Topography imaging with a heated atomic force microscope cantilever in tapping mode". United States. doi:10.1063/1.2721422.
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@article{osti_20953428,
title = {Topography imaging with a heated atomic force microscope cantilever in tapping mode},
author = {Park, Keunhan and Lee, Jungchul and Zhang, Zhuomin M. and King, William P. and Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801},
abstractNote = {This article describes tapping mode atomic force microscopy (AFM) using a heated AFM cantilever. The electrical and thermal responses of the cantilever were investigated while the cantilever oscillated in free space or was in intermittent contact with a surface. The cantilever oscillates at its mechanical resonant frequency, 70.36 kHz, which is much faster than its thermal time constant of 300 {mu}s, and so the cantilever operates in thermal steady state. The thermal impedance between the cantilever heater and the sample was measured through the cantilever temperature signal. Topographical imaging was performed on silicon calibration gratings of height 20 and 100 nm. The obtained topography sensitivity is as high as 200 {mu}V/nm and the resolution is as good as 0.5 nm/Hz{sup 1/2}, depending on the cantilever power. The cantilever heating power ranges 0-7 mW, which corresponds to a temperature range of 25-700 deg. C. The imaging was performed entirely using the cantilever thermal signal and no laser or other optics was required. As in conventional AFM, the tapping mode operation demonstrated here can suppress imaging artifacts and enable imaging of soft samples.},
doi = {10.1063/1.2721422},
journal = {Review of Scientific Instruments},
number = 4,
volume = 78,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}
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Journal Article:
DOI:  10.1063/1.2721422
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  • ; - Review of Scientific Instruments
    This paper presents a method and cantilever design for improving the mechanical measurement sensitivity in the atomic force microscopy (AFM) tapping mode. The method uses two harmonics in the drive signal to generate a bi-harmonic tapping trajectory. Mathematical analysis demonstrates that the wide-valley bi-harmonic tapping trajectory is as much as 70% more sensitive to changes in the sample topography than the standard single-harmonic trajectory typically used. Although standard AFM cantilevers can be driven in the bi-harmonic tapping trajectory, they require large forcing at the second harmonic. A design is presented for a bi-harmonic cantilever that has a second resonant modemore » at twice its first resonant mode, thereby capable of generating bi-harmonic trajectories with small forcing signals. Bi-harmonic cantilevers are fabricated by milling a small cantilever on the interior of a standard cantilever probe using a focused ion beam. Bi-harmonic drive signals are derived for standard cantilevers and bi-harmonic cantilevers. Experimental results demonstrate better than 30% improvement in measurement sensitivity using the bi-harmonic cantilever. Images obtained through bi-harmonic tapping exhibit improved sharpness and surface tracking, especially at high scan speeds and low force fields.« less

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  • ; ; ; ... - Journal of Applied Physics
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