高频超声清洗中声场分布的仿真及实验研究

高频超声乃至兆声清洗广泛应用于半导体器件的超精密清洗,可以有效去除纳米颗粒污染。其中,声能在声场中的分布决定了清洗效果,包括去除均匀性和清洗对象破坏。对于矩形清洗槽内的声场分布,采用简正分解理论直接求解声压分布。结果表明,兆声声能集中于声源辐射轴所在的局部区域,声压波腹和波节分布反映声源振动面形状,而超声波声能扩散至全声场。采用水听器对超声波声场声压分布进行测量,与理论结果相符。由于截断误差和非线性空化误差的存在,理论值小于实验测量结果。

Simulation and experiments research of acoustic field distribution in high frequency ultrasonic cleaning

High frequency ultrasonic,even megasonic bath cleaning has been one of the most successful techniques for nanoparticle removal in semiconductor manufactural.The megasonic energy in sound field determines the cleaning effect,including the uniformity removal and object destruction cleaning.The distribution of sonic pressure in a wet cleaning bath is simulated based on normal mode decomposition theorem.The results show that megasonic wave can focus on the local area of sound radiation zone axis,and the distribution of wave nodes reflects the shape of vibration source,which is different from low frequency ultrasonic with diffuse sound energy.The measurement of ultrasonic sound pressure hydrophone is consistent with the theoretical results.The theory value is lower than the experiment value due to the cut-off error and nonlinear cavitation effect.