Atomic Force
Microscopy
Chemical & Physical Analysis

image: PSIA XE-100 atomic force microscope

PSIA XE-100 atomic force microscope

Atomic force Microscopy (AFM) is a powerful technique that can image the topography of a surface with nanometer resolution, as well as probe its local mechanical and electrical properties. AFM is routinely used to evaluate the surface structure of:

  • Semiconductors
  • Polymers
  • Adhesive materials
  • Biological samples

The XE-100 AFM at Southwest Research Institute (SwRI) operates in various contact and noncontact modes to measure different surface properties:

  • Image soft biological samples without degrading the sample using the noncontact mode.
  • Phase images from the noncontact mode can also indicate regions of different adhesion and stiffness.
  • Reveal areas of different frictional force on an heterogeneous surface by monitoring the lateral force in contact mode.
  • Use the electrostatic force mode to probe the local electrical properties of a surface by applying a voltage between the sample and a conductive AFM tip.

The AFM accepts sample sizes as large as 100 mm × 100 mm × 20 mm thick, with masses up to 500 g. The X-Y scanner can image areas as large as 50 μm × 50 μm, with a resolution of <0.15 nm. The Z scanner can measure surface features as high as 12 mm, with a resolution of <0.05 nm.

image: The topography (left) of a conductive semiconductor device shows a series of interlocking “fingers” separated by trenches. The electrostatic image (right) shows every other finger carries a voltage, while the others are grounded.

The topography (left) of a conductive semiconductor device shows a series of interlocking “fingers” separated by trenches. The electrostatic image (right) shows every other finger carries a voltage, while the others are grounded.

Related Terminology

atomic force microscopy  •  XE-100 AFM  •  surface analysis  •  scanning probe microscopy  •  SPM  •  nanometer resolution  •  materials characterization  •  biological analysis  •  analytical services  •  rheology and texture analysis  •  microscopy  •  nanometer resolution  •  spectroscopy  •  noncontact mode  •  electrostatic force mode  •  contact mode

chemphys.swri.org
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(210) 522-6259, chemphys@swri.org

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04/15/14