Vol. 50, No. 1（論文特集: 2025年度静電気学会全国大会）

論文

直接帯電法を用いたCO₂水の電荷制御によるSiO₂/Siウェハ表面電位制御
Surface Potential Control of SiO₂/Si Wafers Using Direct Charging Method for Charge Control of CO₂ Water

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

静電気学会誌　第50巻　第1号　pp. 14 - 19
2025年9月11日受付
2025年12月16日受理
DOI   https://doi.org/10.34342/iesj.2026.50.1.14

Abstract
Two-fluid spray cleaning using deionized water is used in the semiconductor device manufacturing process. Cleaning with deionized water causes electrostatic discharge (ESD) due to charging of the wafer surface, which can destroy devices on the wafer. Currently, CO₂ water, in which CO₂ gas is injected into pure water, is used to suppress wafer surface charging. However, the mechanism of wafer surface charging has not been clarified. In this study, we focused on the effect of charged droplets on the wafer surface. The amount of charging of CO₂ water was controlled by the direct charging method, in which the liquid was charged by applying a high voltage directly to the flowing liquid. Using this direct charging method, the current generated by the two-fluid spray was measured. When a positive voltage of 10 kV was applied to CO₂ water, a current of about 600 nA was measured. The SiO₂/Si wafer surface potential was measured when the positively charged CO₂ water was sprayed, and the SiO₂/Si wafer surface potential increased by approximately 2 V in the positive direction. These results indicate that spraying charged CO₂ water onto the surface of SiO₂/Si wafers can control the potential of the SiO₂/Si wafer surface.

Keywords
静電気障害，二流体スプレー，CO₂水，帯電，SiO₂/Siウェハ