Investigation of total reflection X-ray fluorescence calibration with picoliter deposition arrays

Picoliter quantities of metal contaminated solutions were deposited on silicon wafers in uniform arrays of residues. Characterization of the residues indicates that they are thin films (<2 nm). With NIST traceable metal standard solutions and knowing the exact volume deposited in an array, a standard calibration wafer for quantifiable contamination control by TXRF can be made. A calibration curve can be generated with arrays of increasing concentration all deposited on a single wafer. We also deposited picoliter arrays of phosphorus solution to explore the feasibility of analyzing for trace phosphorus contamination by TXRF. The best result for the phosphorus analysis (signal to background) was on an Al2O3 surface as compared to silicon or photoresist coated surfaces.

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