Acoustic reflection coefficient of silicon wafers in megasonic cleaning tanks

Abstract

Reflection coefficients of silicon wafers in megasonic cleaning tanks have been determined theoretically and experimentally. The experimental results obtained indicate that the model of a layered solid in liquids is a good predictor of reflection coefficients for silicon wafers in liquids. At a frequency of about 1 MHz, high reflection from silicon wafers occurs at large incident angles. There are also two troughs of low reflection for incident angles between 0/spl deg/-90/spl deg/. The Young's modulus and Poisson's ratio of the silicon [110] orientation give the best agreement between the model and experimental results.