Imaging stability and average tip-sample force in tapping mode atomic force microscopy

In tapping mode atomic force microscopy (AFM), a cantilever is driven near its resonance frequency and intermittently strikes the sample while raster scanned across a surface. The oscillation amplitude is monitored via a feedback loop to construct topography maps of surfaces at the nanoscale. This paper deals with two major limits on scanning rates when operating in air: (1) the slow transient response of the cantilever and (2) instabilities associated with systems with high quality factors (Q). Due to the slow transient response, the AFM has difficulty in instantly responding to steps along the surface, resulting in the need for slower scan rates and higher gains to more accurately track the surface. However, the use of higher gains leads to more pronounced instabilities associated with high Q systems. By driving the cantilever well below its resonance frequency, stability of the system is greatly improved, resulting in better feature tracking and allowing for scanning at higher speeds with larger gains....

[1]  rensen,et al.  Role of attractive forces in tapping tip force microscopy , 1997 .

[2]  B. V. Derjaguin,et al.  Effect of contact deformations on the adhesion of particles , 1975 .

[3]  Todd Sulchek,et al.  High-speed tapping mode imaging with active Q control for atomic force microscopy , 2000 .

[4]  Joseph L. Garbini,et al.  Optimal control of force microscope cantilevers. I. Controller design , 1996 .

[5]  J. Vesenka,et al.  Colloidal gold particles as an incompressible atomic force microscope imaging standard for assessing the compressibility of biomolecules. , 1993, Biophysical journal.

[6]  L. Nony,et al.  Nonlinear dynamical properties of an oscillating tip–cantilever system in the tapping mode , 1999, physics/0510099.

[7]  A. Mikhailovsky,et al.  Phase-sensitive spectroscopy of surface plasmons in individual metal nanostructures , 2004 .

[8]  Joseph L. Garbini,et al.  Optimal control of ultrasoft cantilevers for force microscopy , 1998 .

[9]  Georg Schitter,et al.  State-space model of freely vibrating and surface-coupled cantilever dynamics in atomic force microscopy , 2004 .

[10]  Ricardo Garcia,et al.  Attractive and repulsive tip-sample interaction regimes in tapping-mode atomic force microscopy , 1999 .

[11]  Todd Sulchek,et al.  Characterization and optimization of scan speed for tapping-mode atomic force microscopy , 2002 .

[12]  Ricardo Garcia,et al.  Dynamics of a vibrating tip near or in intermittent contact with a surface , 2000 .

[13]  Ricardo Garcia,et al.  Dynamic atomic force microscopy methods , 2002 .

[14]  J. Israelachvili.  Intermolecular and surface forces , 1985 .

[15]  Pascal Gallo,et al.  How does a tip tap? , 1997 .

[16]  Murti V. Salapaka,et al.  Linearity of amplitude and phase in tapping-mode atomic force microscopy , 2000 .

[17]  Jerome Mertz,et al.  Regulation of a microcantilever response by force feedback , 1993 .