Relationship between Atmospheric Humidity and Watermark Formation in IPA Dry of Si Wafer after HF Clean
As the critical dimension of LSI continues to decrease, the surface tension of water and its effect on the formation of watermarks is becoming a significant problem. It is known that watermarks are easily generated when a silicon hydrophobic surface is dried in a wet cleaning process. Many studies about watermarks have been reported [1, 2]. Additionally if the rinse and dry steps were performed under an inert (nitrogen) ambient and the rinse water had low oxygen concentration, watermarks could be effectively avoided [3, 4].
Paul Mertens, Marc Meuris and Marc Heyns
N. Kurumoto et al., "Relationship between Atmospheric Humidity and Watermark Formation in IPA Dry of Si Wafer after HF Clean", Solid State Phenomena, Vols. 145-146, pp. 91-94, 2009