Particulate emissions from equipment used in ultra clean areas of the semiconductor industry

Equipment used in ultra clean manufacturing processes emits particles during operation due to friction processes. These emitted particles have a major impact on the air cleanliness in controlled production environments. Even particles in the nanometer range can damage the processed component, for example a semiconductor wafer. The requirements of cleanliness levels for the semiconductor industry increase steadily because of the continuous decreasing pitch widths processed on the wafers. Currently, half pitch widths of 22 nm or even below are discussed using extreme ultraviolet lithography. A measurement and classification system for the clean room suitability of equipment is described, which is directly related to the already established ISO-classification system of clean rooms. Based on this, a new international standard "Clean room Suitability of Equipment" is currently under development within the ISO 14644-family. This new standard will provide the missing link between equipment and the respective cleanliness classes in near future.