Applications Of Ion Chromatography And Preconcentrator-Gas Chromatography-Mass Spectrometer In Semiconductor Defect Research

With the development of semiconductor technology, wafer CD hasreached nanometer level. More and more defects are emerged in whichcrystal defect and crater defect are two typical defects. Crystal defect is acrystalloid defect which appeared in wafer pad. Crater defect is appearedafter copper CMP process due to copper was pulled out during CMP period.These two defects are the killer defects in semiconductor manufacturingprocess which will induce wafer scrap.In order to research the cause of defects formation, the defectselimination and control, more and more high precision analysisinstruments and analysis methods are required in which IonChromatography and Gas Chromatography-Mass Spectromer are twoimportant instruments.Ion Chromatography and Preconcentrator-Gas Chromatography-MassSpectrometer were used for crystal defect and crater defect research. Theenvironment contaminant which induced the two defects was studied andthe control method of the contaminant was also discussed in this research.Wafer pads were found to be contaminated by pod and cassette innerenvironment evidenced by the formation of crystal defects. The rootcause and its associated solution for contaminant were also suggested.The contaminant contributions from different Fab modules andmanufacturing processes were discussed. Furthermore, the mechanism ofcontaminant formation and its removal were elucidated.VOC of cleanroom environment was found to be the most important root cause for crater defect formation. Both outside air and parts used incleanroom were proved to be the VOC source. And the mechanism ofcrater defect formation was elucidated.The control method of fluoride and VOC contamination wereclarified. The validity of the control method were alsoe be confirmed inthis research.This research illuminated a clear study way for production defectwhich caused by molecular contaminant in environment. It is asuccessful experience for analysis tools application in defect research.