Development of Simultaneous Removal System for Trace Gaseous and Particulate Contaminants by UV/Photoelectron Method

本研究旨在开发一种在常压和减压条件下利用紫外光/光电子法同时去除有机、气态和颗粒物污染物的内置式系统。第一年，我们在常压下进行了脱除气体和颗粒物的实验，结果表明，脱除装置对它们具有稳定的高脱除效率。在第二年，我们修改了装置，使其可以在亚大气压(直到20托)下运行，并进行了类似于正常压力条件的实验。结果表明，在100torr以下，颗粒去除效率迅速提高；ii)考虑颗粒充电效率的对流扩散方程的数值计算可以估算出每个压力下的去除效率；iii)紫外光/光电子的发射可以抑制液滴接触角的增加，这是其有机污染的一个指标；iv)同时使用紫外光/光电子发射器和紫外光照射的二氧化钛可以在常压和减压下获得极高的气体污染物去除效率。

This research aims at developing a stocker built-in simultaneous removal system for organic gaseous and particulate contaminants by UV/photoelectron method under both normal and reduced pressures. In the first year, we conducted experiments on removal of gaseous and particulate matter under atmospheric pressure, and then obtained the result that the removal device has steadily high removal efficiency for them. In the second year, we modified the setup so that it can operate under subatmospheric pressure (until 20 torr) and performed experiments similar to the normal pressure conditions. As a result, it was shown that i) particle removal efficiency increased rapidly under 100 torr, ii) the numerical calculation of convective-diffusive equation for particles accounting for their charging efficiency can estimate their removal efficiency at each pressure, iii) the emission of UV/photoelectrons can suppress increase in contact angle of droplets on wafer set in the stocker, which is an index of its organic contamination, iv) the simultaneous usage of UV/photoelectron emitter and UV-irradiated titania can achieve extremely high efficiency for gaseous contaminants at both normal and reduced pressures.