Adhesion between highly rough alumina surfaces: An atomic force microscope study

The removal of contaminant particles in microelectronics processes now extends not only to the compounds themselves but also to the reactor pieces where they are fabricated. This raises new issues as both the particles and the reactor walls are highly rough and a maximum number of particles per unit area is tolerated. In this work we study the adhesion force of a sapphire particle onto alumina substrates of roughness ranging from 10 nm to 3 μm peak-to-peak on a 5 μm × 5 μm area, in water. A contribution of this work is the prediction of the statistic of the adhesion force by a fast running numerical computation, without any adjustable parameters. The perspective is to be able to predict the best conditions for removing contaminant particles.