Qualification of particle surface probe : requirements and development of a test bench
Congress title :11th International Symposium on Particles on Surfaces: Detection, Adhesion and Removal
Congress location :Orono
Congress date :16/07/2008
For high-tech industries, such as semiconductor or optical ones, controls must be done not only on airborne particle contaminants in cleanrooms but also on surface particle contamination. Nowadays, an international standard is on progress: ISO 14644-9. This standard "Cleanrooms and associated controlled environments Part 9: Classification of surface particle cleanliness" describes the classification of the particle contamination levels on solid surfaces in cleanrooms. Recommendations on testing and measuring methods as well as information about surface characteristics are given in informative annexes. This standard applies to all solid surfaces such as walls, ceilings, floors, working environment, tools, equipment and devices. The surface particle cleanliness classification is limited to particles between 0.05 µm and 500 µm.
In order to classify the particle contamination on metallic or plastic or glass surfaces, surfacic commercial probes exist but none of them are correctly calibrated. In this paper, a qualification bench developed in collaboration between CEA and IRSN is described and the results obtained for a surfacic probe based on airflow particle resuspension and optical particle counter measurement are presented. The effects of particle-surface natures and particle diameter are discussed on the bases of resuspension efficiency and transmission-detection efficiency for particles between 30 µm and 80 µm.