Tapping-mode tuning fork force sensing for near-field scanning optical microscopy

Abstract

A tapping-mode tuning fork force-sensing method for near-field scanning optical microscope is reported. Use of the tapping-mode tuning fork with mechanically asymmetric excitation generates better stability and sensitivity than in the shear force mode. Comparison of force curves for the two methods demonstrate that the tapping-mode tuning fork method provides a simpler and more sensitive method for near-field measurements. The method is demonstrated by imaging a sample consisting of 500 nm standard polystyrene spheres on silica in both air and water.

Advances in atomic force microscopy

“…Bartzke et al (1993) proposed the ''needle sensor,'' a force sensor based on a quartz bar oscillator. Rychen et al (1999) and Hembacher et al (2002) demonstrated the use of quartz tuning forks at low temperature, and other applications of quartz tuning forks as force sensors can be found in Edwards et al (1997); Ruiter et al (1997); Todorovic and Schulz (1998); Tsai and Lu (1998);Wang (1998);and Rensen et al (1999). Quartz tuning forks have many attractive properties, but their geometry gives them marked disadvantages for use as force sensors.…”

Atomic resolution on Si(111)-(7×7) by noncontact atomic force microscopy with a force sensor based on a quartz tuning fork

“…Tuning forks have been used in scanning probe microscopes before. [9][10][11][12][13][14][15][16][17] However, atomic resolution has not been reported so far.…”

<title>High-resolution near-field measurements of microwave circuits</title>

“…During the first step the topography acquisition is performed using an AFM-like (Atomic Force Microscopy) technique where a glass probe is dithered perpendicular to the surface and the dependency of the amplitude and the phase of the mechanical oscillation of the probe on the probe/sample separation is used to keep the separation constant in the range of several tens of nm. A quartz tuning fork [5,6] in a single oscillating arm configuration [7] is utilized for probe frequency stabilization and amplitude detection. The technique can be employed with all types of materials used in circuit fabrication to include various metals, dielectrics and semiconductors.…”