Characterization of ejected particles during laser cleaning

Abstract

Laser cleaning is a prospective cleaning method that can be widely used in microelectronics fabrication, archive restoration, and optical apparatus cleaning. Removal of particles from a solid substrate is an important aspect of laser cleaning. Although many studies have been carried out on this subject, few of them are objected to the characterization of the ejected particles in laser cleaning. In this article, a method was developed to "capture" the particles ejected from the substrate after laser irradiation. Detection of both angular distribution and ejection energies was achieved with this method. It was found that the angular distribution of the ejected particles fitted to a Gaussian curve when the laser irradiated normally to the substrate. The distribution curve for the particles ejected from a rough surface has a wider full width at half maximum than that from a smooth substrate. It was also found that the particle ejection energy increased obviously with laser fluence, therefore the laser cleaning efficiency was promoted sharply as laser fluence increased. © 2000 American Institute of Physics.