The ECO-SNOW® Extreme Lithography Cleaning System (EL-C™) removes nanometer-scale particle contamination for applications such as full mask clean, final clean, persistent particles, post repair debris clean, removal of adders from other equipment, glass side clean and mask blank cleans. The system provides damage free cleaning for optical masks with SRAFs down to 37nm. The system also allows for development of cleaning processes for EUV masks. ECO-SNOW® cleaning is a fast, environmentally friendly, “all dry” non-contact process that offers numerous advantages that compliment conventional wet clean systems. EL-Cplus is the newer replacement version for the EL-C with certain upgrades for improved performance.