Influence of Temperature Field on Generation Characteristics of Nano-Bubbles and Their Application to the Environmental Friendly Cleaning Technology

在温度对纳米气泡生成特性的影响方面，随着温度的降低，纳米气泡的生成量增加。这可能是由于在较低温度下液体的气体饱和容量增加。在较低的温度下，饱和气体的总量会增加，从而增加释放的气体量，从而产生更多的纳米气泡。针对纳米气泡的清洗效果，制作了液体循环实验装置，通过对液体施加超声波产生纳米气泡。对于被污染的极板，选择极板上微小颗粒污染作为半导体行业实际技术需求的典型例子。在以几米/秒的速度流动的液态水中，实现了提供纳米气泡的应用。实验结果表明：(1)纳米气泡的产生，对超净液态水施加850kHz的超声波，10ml可产生约8000个直径在500nm ~ 1000nm之间的纳米气泡。(2)利用超净液态水滞流的纳米气泡，对近50nm氧化铝细颗粒污染的污染板进行清洗，实际达到了体积比99%、面积比92%的清洗效果。否则，仅应用超净液态水或含有微米级气泡的液态水，没有观察到明显的清洁效果。

As for the influence of the temperature on the generation characteristics of nano-bubbles, the amount of generating nano-bubbles was increased according to the lowering of the temperature. This would be due to the increased gas saturation capacity to the liquid for the lower temperature. At the lower temperature, the total amount of the saturated gas would be increased and thus the released gas amount would be increased to make the larger number of nano-bubbles.As for the cleaning effect of nano-bubbles, the liquid circulating experimental apparatus was manufactured and nano-bubbles were generated by applying the ultrasonic waves to the liquid. For the contaminated plate, the minute particle contamination on the plate was selected as the typical example of the actual technical needs to the semiconductor industries. The application of supplying nano-bubbles was realized by contained in the liquid water flow with the velocity of several meters per second.The following conclusion were obtained from the experimental results.(1)As the generation of nano-bubbles, about 8000 nano-bubbles with the diameter between 500nm and 1000nm were able to be generated for 10ml by applying ultrasonic waves of 850kHz to the ultra-clean liquid water.(2)By applying nano-bubbles with the stagnation flow of ultra-clean liquid water to the contaminated plate which was contaminated by the nearly 50nm alumina fine particles, cleaning effects was actually realized by the amount of 99% for the volume ratio, and 92% for the area ratio. Otherwise, by applying only the ultra-clean liquid water or the liquid water containing micrometer scale bubbles no significant cleaning effects was observed.