Impact of Steam-Water Mixed Spray on Silicon and Metal Surfaces

Performance of photoresist stripping using steam-water mixed spray is quantitatively investigated with water flow rate as the operating parameter. The most striking and the most important finding is that air-water mixed spray turns out hardly effective. This result shows the peculiar superiority of the proposed technique. As we found that the prominently excessive long time of spraying of steam-water mixture on metal surface results in surface abrasion, this result strongly suggests that both the resist strippping and metal surface abrasion are dominated by essentially the same mechanism. We speculate that our proposing technique is categorized in the physical force cleaning. We discuss the role of the water flow rate in this cleaning technique and the validity of the assumption of physical force cleaning.