超临界CO_2萃取硅表面有机污染物研究

Extraction of Organic Materials from Wafer Surface by Supercritical Carbon Dioxide

研究利用超临界CO2萃取方法去除硅片上有机污染物的效果。通过用润滑油模拟有机污染物,对污染量、萃取压力、萃取温度做正交实验,分析去除率;对萃取前后的硅片做电镜扫描实验、X射线光电子谱扫描实验,分析硅片型貌和电子结构变化。实验结果表明,去除率随着压力和温度的升高而升高,但温度的影响程度小于压力;去除效果随着污染量的增加而略有降低,但去除率均在92%以上;电镜扫描图片显示,萃取前后硅片型貌没有发生变化;X射线光电子谱扫描图显示,除了碳污染水平不同,萃取前后的硅片表面电子结构基本相同。

This paper studies supercritical carbon dioxide extraction technology for removing organic contaminants from wafer surface. Engine oil is used as the organic contaminant; orthogonal testing on pressure, temperature and mass is used to analyze the cleaning efficiency; scan electrical mirror scanning testing and X-ray photoelectron spectra scanning testing on wafer surface are used, respectively, to see whether the appearance and electron structure are changed after extracting. Results show that the cleaning efficiency is improved with the increasing pressure and temperature, but, with pressure taking a bigger share. Even though the efficiency is a little lowered with a larger mass, the cleaning efficiency is over 92%. Scan electrical mirror pictures show that the appearance of the wafer is not changed after extraction, scanning pictures of wafer surface by X-ray photoelectron spectra show that the electron structure of the wafer is by and large in the same homology after extraction except for the difference of carbon contaminant level.