Development of the evaluation method of total organic contaminants on silicon wafer surface by Combustion API-MS method

摘要

The assessment of airborne molecular contaminants has become an important technology in the semiconductor manufacturing. The conventional organic contamination analysis methods, such as WTD-GO-MS and TD-IMS, are very effective in a qualitative analysis and a quantitative analysis. The new analysis method is, however, needed for the total organic contamination analysis. The combustion-API-MS method was developed for the determination of total carbon concentration on the silicon wafer surface. As the examination of the combustion-API "MS method, the thermal behavior of three kinds of organic compounds (Di-2-ethylhexyl-phthalate, Tri- butyl-phosphate, Tri-2-chloroethyl phosphate) was examined by TG/DTA. DOP was burned by the programmed heating in air. On the other hand, TBP and TCEP were vaporized by the programmed heating in air. As the results of recovery test, the recovery rates of DOP and TCEP obtained 90 percent or more, but the recovery rate of TBP was about 70 percent. In the examination of combustion-API-MS method for high vapor pressure organic compound, the addition method of standard has to be improved. However, it was found that the combustion-API-MS method was effective in the total carbon concentration analysis for all organic contamination. The improvement in sensitivity and the new application of the combustion-API-Ms method will be studied.