SESHA 2011 Symposium / SIA IHTESH 2011 --- Abstract

Surface Contamination of Dummy Wafer and its Health Effect in Semiconductor Manufacturing Industry

Choi, Kwangmin
(Samsung Electronics Co. LTD)

Dummy wafer has been effectively used to monitoring of equipment and process in semiconductor manufacturing industry. However, it has been predicted human health impacts by hazardous by-products which could be generated on the wafer surface by chemical reaction of various precursors such as toxic gases and chemicals. Although there has been much attention on the issue, it has not been studied yet. In this study, therefore, we have explored the surface contamination of the dummy wafers which have been used in semiconductor processes by quantitative and qualitative analysis methods. From the results of the organic contamination analysis of the dummy wafers at room temperature, it could not be confirmed some specific compounds, except that a few components such as toluene and siloxane were detected less than 1 ppbv. Further, we also found that ion (NH4+, F-, NO2- etc.) and metal contaminations (Al, Si etc.) of the dummy wafer surface are similar to those of blank(i.e., bare wafer), whereas it was detected ca. 70~90 ppb of Si on the surface of wafers used Etch and Diff decap process. From the TDS(50~900℃) results, meanwhile, the dummy wafer used only Etch process out-gassed CxFy, CxOy and CxHy contaminants which are induced by process gases such as CF4, CHF3, C3F8 etc. However it could be mentioned that the operatorís exposure by the CxFy, CxOy and CxHy has little possibility because the dummy wafer becomes de-gassed and room temperature after finished process and/or monitoring. The present results showed that the surface of dummy wafer had not contained by-products which are hazardous to human health. The dummy wafer used only Etch process out-gassed CxFy, CxOy and CxHy contaminants which are induced by process gases such as CF4, CHF3, C3F8 etc. However it could be mentioned that the operatorís exposure by the CxFy, CxOy and CxHy has little possibility because the dummy wafer becomes de-gassed and room temperature after finished process and/or monitoring.