The impact of organic contamination on wafer surfaces on the functionality of nanostructures and advanced microelectronics becomes crucial as the continuously shrinking feature sizes become similar to the dimensions of molecules and clusters of molecules. Especially, manufacturing of highly integrated circuits requires clean surfaces as processes might cause defects involving for example carbon and sulfur. The approach to study organic contamination on wafer samples using different analytical tools enables the detection of the whole range of organic compounds including non‐volatile and volatile ones. For the studies the methods used were synchrotron radiation based Near Edge X‐ray Absorption Fine Structure (NEXAFS) in the soft X‐Ray range at the absorption edges of light elements (e.g. C, N, O, F) combined with reference‐free Total‐reflection X‐Ray Fluorescence (TXRF) analysis, Thermal Desorption Gas Chromatography Mass Spectrometry (TD‐GCMS), and Time of Flight Secondary Ion Mass Spectrometry (TOF‐SIMS). TOF‐SIMS analysis of the surfaces of wafers from the lithography process after ashing showed sulfur compounds related to resist residues not identified by TD‐GCMS. The source of the sulfur is assumed to be a photo acid generator of the resist. It was proven by TD‐GCMS and TXRF‐NEXAFS that final clean and packaging were the process steps during which detectable organic contamination was transferred to the wafer surface during wafer manufacturing. Multi‐criteria evaluation of the TXRF NEXAFS spectra was used to compare the results with TD‐GCMS. The TXRF‐NEXAFS results are in good agreement with the TD‐GCMS results. The advantage of TXRF‐NEXAFS and TOF‐SIMS are the sensitivity for organic contaminants that are not detectable by TD‐GCMS, due to their high boiling point and low vapor pressures.
- X-ray absorption near edge structure
- Semiconductor surfaces
- Surface cleaning
- Atomic and molecular clusters
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