Effect of Different Deposition Mediums on the Adhesion and Removal of Particles

The purpose of this study is to investigate the effect of the different deposition mediums on the adhesion and removal of particles. Polystyrene latex (PSL) particles (50 mu m) are deposited on thermal oxide and silicon nitride coated silicon wafers using different suspension mediums: air, isopropyl alcohol (IPA), and deionized water and then removed in a dry environment. The results show that PSL particles deposited on oxide are easier to remove than those on nitride due to a higher van der Waals force in all deposition mediums. In addition, dry particles deposited in air are much easier to remove than those desposited in a liquid medium. When particles are deposited from a liquid suspension, a liquid meniscus is formed between the particle and the substrate, resulting in a capillary force. The capillary force induces a plastic deformation for soft particles such as PSL, which increases the contact area between the particle and the substrate, making them more difficult to remove. The liquid meniscus evaporates shortly after it is exposed to either a dry air environment or vacuum; however, the plastic deformation of particles would take place mainly due to the initial adhesion force in addition to the short time exposure of the capillary force. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3377090] All rights reserved.