Steam laser cleaning

In contrast, laser irradiation has been shown to provide a potential solution to this problem. Laser-induced removal of the contaminants can be effected either via direct absorption of the laser light by the particles and/or the substrate ( dry laser cleaning ) or via the prior application of a liquid film ( steam laser cleaning ) [3]. The particle removal process can be evaluated either directly, by post-treatment optical or scanning electron microscopic examination of the sample, or indirectly via the scattering by the par-... 

Fig. 6 Schematic diagram of a typical apparatus developed for industrial use of steam laser cleaning. The wafer is kept face down in order to avoid resettlement of the removed particles. Alcohol is commonly added to the water for improving wetting of the surface...

Because the exerted forces are about ten times higher than those developed by the thermal expansion of the substrate, laser steam cleaning efficiencies are much higher than those in dry cleaning. This permits the use of lower laser fluences, which is particularly important for heat-sensitive sub-... 

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