The methods of photomask cleaning used by the mask makers have been derived from the developments in the semiconductor industry. The understanding of the science of wafer cleaning has advanced significantly in the last decade. However, the past requirements for mask makers have not necessitated an in-depth study of the surface phenomena that dictate the mechanisms for particle adhesion and removal. A survey of the understanding developed in the wafer industry was conducted. Applications relevant to mask making have been identified. Based on this study, areas for future investigations in mask cleaning technology have been recommended.
Rajeev R. Singh, Rajeev R. Singh,
"Photomask cleaning: areas for future focus", Proc. SPIE 2322, 14th Annual BACUS Symposium on Photomask Technology and Management, (7 December 1994); doi: 10.1117/12.195812; https://doi.org/10.1117/12.195812