Thomas H. Kuehn, Fellow
David B. Kittelson, Co-Principal Investigator

Modeling and Numerical Simulation of Megasonic Cleaning

The objective of this research team was to develop a model based on first principles to predict contaminant particle removal from silicon wafers in megasonic tank cleaning systems. Such a model could be used to design new generation cleaning equipment by varying parameters such as:

• Transducer shape, frequency, and power input
• Tank geometry, transducer location, and pumped flow conditions
• Wafer spacing, carrier design, and location
• Liquid temperature and dissolved gas concentration

The project included two parts. The first was to improve the model for the three-dimensional megasonic energy field in a speciallydesigned, well-instrumented megasonic cleaning tank. This type of tank is used to remove submicron particles from the surfaces of silicon wafers and electronic parts or to chemically process silicon wafers in a semiconductor manufacturing process.

The second part of the project was to correlate cleaning efficiency (particle contaminant removal) with the local sound density distribution, the microstreaming field, and cavitation intensity distribution. The modeling method, calculated results, and final report provided industrial users information for evaluating and improving megasonic cleaning systems.

Research Group

Luis Cardon, Salta, Argentina
William Gerstler, Graduate Student Researcher
Humberto Ortiz, Graduate Student Researcher
Yi Wu, Graduate Student Researcher
Ching-Hsu Yang, Graduate Student Researcher