Feature

Laser Cleaning Techniques for Critical Surfaces

Susan D. Allen, S. J. Lee, and K. Imen

Organics, as exemplified by the fingerprint, and particulates or dust on optical surfaces are familiar problems for anyone in optics. For critical optical surfaces such as those exposed to high intensities, or where minor contamination significantly degrades performance, such contamination can be more than just a nuisance, causing optical component damage or extensive downtime for cleaning and part replacement. For state-of-the-art semiconductor devices, low level metal contamination also must be removed. The cleaning of critical surfaces must, therefore, address organics, inorganics—particularly metals, and particulates. Because of potential recontamination of cleaned surfaces by liquids, an ideal cleaning technique would utilize gas phase reactants to produce gas phase products that could be easily removed from the system. Promising optically based cleaning methods for organics and particulates are being developed and optical techniques for metal removal are possible.