Detachment Energy Evaluation in Nano-Particle Cleaning Using Lateral Force Microscopy

Abstract

It has been difficult to detach abrasive particles smaller than 50 nm from polished surfaces in post-CMP cleaning. During the cleaning process, the residual nano-particles exert shear force in the inevitable shear flow. In order to understand the cleaning mechanism, it is indispensable to investigate not only the force but also the energy acting on different-sized nano-particles. In this article, we proposed the evaluation of detachment energy (the energy required to detach nano-particles) by using Lateral Force Microscopy. As an example, the dominant detachment energy of the silica nano-particle between the oxide film is the potential energy of the hydrogen bond. It suggested that the silica nano-particle detachment involves the breaking of hydrogen bonds.

Keywords

• detachment energy
• hydrogen bond
• shear flow
• lateral force microscopy
• post-CMP cleaning
• SiO₂ nano-particle