Airborne PM2.5 characteristics in semiconductor manufacturing facilities

This study aimed to elucidate the concentrations and physicochemical properties of airborne PM2.5 during the normal operation of process equipment and scrubber in semiconductor manufacturing facilities, including the clean room (CR), plenum, clean sub fab (CSF), and facility sub fab (FSF). Number and mass concentrations of PM2.5 in the main facilities, such as the CR, plenum and CSF ranged ND-4.766 #/cm3 and ND-1.072 µg/m3, respectively, and for FSF, ranged 9.261–134.088 #/cm3 and 0.574–25.941 µg/m3. The concentration levels of PM2.5 in the FSF (excluding CR, plenum, and CSF) were partially affected by the PM levels in outdoor air. The particles of 0.3–1.0 µm corresponding to PM1 for number and mass concentrations accounted for 98.44–99.67% and 75.00–96.43%, respectively, of PM2.5, which contains 0.3–2.5 µm particles. In all particles, O and Si were detected in common, and also Al, F, Fe, Mg, K, Ca, and Ti elements were intermittently detected according to the sample. The elemental compositions of airborne particles in the FSF were almost coincident with those of the particles sampled in outdoor air. No particles were evident on the filter media in the CR and CSF. The morphology of the observed particles was spherical and nearly spherical based on the primary particle, and the size ranged approximately 1.5–6.0 µm, which means that particles were likely to be formed by the agglomeration and/or aggregation of primary particles of less than 100 nm. These results can provide useful information for the development of alternative strategies to improve the work environment and worker’s health in the semiconductor industry.