Dependence of Particle Size on the Removal of Particles on a Silicon Surface by Using Electrostatic Force

Abstract

  Removal of small glass spheres on a Si substrate by using adhesion forces between particles and dielectric films was investigated. An upper Si electrode and a dielectric film such as that of polyethylene or polyvinylchloride were placed on a lower Si electrode to which small glass spheres were adhered, and a high voltage was applied to the two Si electrodes for 60 s. The glass spheres had a diameter of 2-20 μm and were adhered to the dielectric film; about 40-50% of the spheres were removed from the Si substrate in the first iteration of a removal process. The removal process was repeated several times, and a high removal rate of about 80% was obtained after the fifth iteration. This implies that the largest glass spheres were removed in the first iteration, and smaller ones were removed in subsequent iterations. The dependence of the particle removal rate on the particle size was evaluated as the ratio of the adhesive force between the particle and film and that between the particle and substrate. Further, it was found that the particle size decreases with the removal rate. This result was in agreement with the experimental result.