Substrate Morphology and Particle Adhesion in Reacting Systems

Force measurements with the atomic force microscope: Technique, interpretation and applications

“…This model was applied to colloid probe measurements between polystyrene spheres and a silicon wafer at different pH values that caused different surface roughness [559] and measured adhesion forces agreed much better with this model than with DLVO theory of a sphere/plane geometry. On the basis of this model, Cooper et al [351,560] generated computer representations of surface topographies as obtained by AFM imaging by distributions of hemispherical asperities and simulated adhesion forces between these surfaces.…”

Hamaker Constants in Integrated Circuit Metalization

“…VDW forces are important to quantify in adhesion studies because they are always present and are always attractive. VDW forces dominate the interaction of particles in contact with thin films (6)(7)(8)(9) and can also be the controlling forces in film adhesion, contributing to adhesive or cohesive film failure (9). Within the equation that describes VDW forces, the Hamaker constant is a key parameter that describes how strongly two materials interact.…”

“…The adhesion forces were also measured by bringing the spheres into contact with the surface and measuring the force required to pull them off. An adhesion model described elsewhere was used to interpret these pull-off measurements (6)(7)(8). This model isolates the contribution of the geometry, morphology, and mechanical properties of the two surfaces to the adhesion force, so that the VDW forces between the surfaces can be described and the Hamaker constant can be determined.…”

“…The new method involved bringing the spheres into contact with the surface and measuring the interaction force as they are pulled out of contact. The Hamaker constant is calculated from the force measured as the cantilever is removed from the surface using an adhesion model developed previously (6)(7)(8)(9) which accounts for the effects of surface roughness, particle geometry, and elastic properties of the interacting materials in the measured adhesion force. In this work Hamaker constants were determined for interactions involving copper, silver, titanium nitride, silicon dioxide, parylene-N, and PTFE.…”

Prediction of Inter-particle Adhesion Force from Surface Energy and Surface Roughness

“…However, for particles with rough surfaces within the same size range, the particle size can be replaced by the surface roughness in estimating the influence of the adhesion force because real contact occurs only at the tips of the surface asperities [15]. It is emphasized that the particle size, which is part of the Bond number calculation, is still the dominant factor; however, the surface roughness has a significant effect on the adhesion force of up to orders of magnitude [16][17][18]. For particles of diameter 10-100 µm, it has been shown that the measured adhesion force is smaller than the theoretical due to reduction in contact area as a result of surface roughness [19,20].…”