超音波水流に基づく洗浄

This review is concerned with a physical cleaning method based on ultrasound-superposed water jets that collide with cleaning targets and spread over their surface; this method is called ultrasonic water flow cleaning and can be used in semiconductor manufacturing processes. Visualization of the acoustic wave and cavitation bubbles in ultrasonic water flow is presented to examine the role of bubbles oscillating under ultrasound irradiation in the process of removing small silica particles from glass surfaces. The visualization results suggest that hydrodynamic force from single-phase water flow does not suffice for particle removal and that acoustic cavitation bubbles play a major role in particle removal as in the case of ultrasonic bath immersion cleaning.