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Title: Manipulation of polystyrene nanoparticles on a silicon wafer in the peak force tapping mode in water: pH-dependent friction and adhesion force

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.4914354· OSTI ID:22399255
;  [1];  [1]
  1. Center of Smart Interfaces, Technische Universität Darmstadt, Alarich-Weiss-Str. 10, 64287 Darmstadt (Germany)

The friction force between nanoparticles and a silicon wafer is a crucial parameter for cleaning processes in the semiconductor industry. However, little is known about the pH-dependency of the friction forces and the shear strength at the interface. Here, we push polystyrene nanoparticles, 100 nm in diameter, with the tip of an atomic force microscope and measure the pH-dependency of the friction, adhesion, and normal forces on a silicon substrate covered with a native silicon dioxide layer. The peak force tapping mode was applied to control the vertical force on these particles. We successively increased the applied load until the particles started to move. The main advantage of this technique over single manipulation processes is the achievement of a large number of manipulation events in short time and in a straightforward manner. Geometrical considerations of the interaction forces at the tip-particle interface allowed us to calculate the friction force and shear strength from the applied normal force depending on the pH of an aqueous solution. The results clearly demonstrated that particle removal should be performed with a basic solution at pH 9 because of the low interaction forces between particle and substrate.

OSTI ID:
22399255
Journal Information:
Journal of Applied Physics, Vol. 117, Issue 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English