Evaluating the Removal of Polystyrene Latex Particles Using the Quartz Transducer Ultrasonic Cleaners in the Megahertz Frequency Range

The removal of nanometer-sized particles is necessary along with a shift to microfabrication and highly integrated semiconductor chips. Spray-type ultrasonic cleaning methods are currently used to clean semiconductors. However, this method has the problem of collapsing wiring patterns due to severe fluctuations in the sound pressure impinging on the substrate surface. We developed a quartz transducer ultrasonic cleaner (QTC) to solve the problem of constant variations in sound pressure. In this study, we conducted experiments on the removal polystyrene latex particles from the surface of silicon wafers using QTC and elucidated the physical particle removal mechanism.