Megasonic Cleaning is a type of Acoustic cleaning, related to Ultrasonic cleaning. It is a gentler cleaning mechanism, less likely to cause damage, and is currently used in wafer cleaning.
Similar to Ultrasonic cleaning, megasonics utilizes a transducer, usually composed of Piezoelectric Crystals to create megasonic energy. Megasonic energy is of a higher frequency (800–2000 kHz) than typical ultrasonic cleaners (<100 kHz). As a result, the cavitation that occurs is gentler and on a much smaller scale. Megasonics are currently used mainly in the silicon industry.
Megasonics cleaning compared to ultrasonic cleaning - The difference between ultrasonic cleaning and megasonics cleaning lies in the frequency that is used to generate the acoustic waves. Ultrasonic cleaning uses lower frequencies; it produces random cavitation. Megasonics cleaning uses higher frequencies at 1000 kHz; it produces controlled cavitation.
An important distinction between the two methods is that the higher megasonic frequencies do not cause the violent cavitation effects found with ultrasonic frequencies. This significantly reduces or eliminates cavitation erosion and the likelihood of surface damage to the product being cleaned. Parts that would be damaged by ultrasonic frequencies or cavitation effects can often be cleaned without damage in a megasonic bath using the same solution.
With ultrasonics, cavitation occurs throughout the tank, and all sides of submerged parts are cleaned. With megasonics, only the side of the part that is facing the transducer(s) is cleaned.
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