Vol. 50, No. 1（論文特集: 2025年度静電気学会全国大会）

論文

純水二流体スプレー時のSiO₂/Siウェハ帯電挙動
Electrostatic Charging Behavior of SiO₂/Si Wafers During Two-Fluid Spray of Deionized Water

伊藤　康生，渡部　一哲，森　竜雄，一野　祐亮，田岡　紀之，清家　善之
Kousei ITO, Ittetu WATANABE, Tatsuo MORI, Yusuke ICHINO, Noriyuki TAOKA and Yoshiyuki SEIKE

静電気学会誌　第50巻　第1号　pp. 20 - 25
2025年9月11日受付
2025年12月18日受理
DOI   https://doi.org/10.34342/iesj.2026.50.1.20

Abstract
In semiconductor manufacturing, two-fluid DI water spray cleaning is widely used but can induce electrostatic charging on SiO₂ surfaces, leading to potential ESD damage. In this study, we experimentally examined the charging behavior of SiO₂/Si wafers during spraying by measuring surface potentials before and after cleaning. The wafer center became negatively charged, whereas the edge became positively charged, indicating charge separation during droplet impact and liquid-film flow. The surface potential increased exponentially with the tangential film velocity. Based on SiO₂ surface chemistry, DI water contact promotes silanol (Si-OH) deprotonation, forming SiO^- and H₃O⁺. The outward flow then transports H₃O⁺ to the wafer edge, causing positive charging. These findings show that both triboelectric and chemical effects contribute to charging during two-fluid spray cleaning.

Keywords
二流体スプレー洗浄，純水，半導体，帯電，静電気障害