Wafer thermal desorption spectrometry in a rapid thermal processorusing atmospheric pressure ionization mass spectrometry

摘要

This paper demonstrates the possibility of performing thermalndesorption spectrometry (TDS) on wafers in an atmospheric pressure rapidnthermal processor (RTP). A special gas sampling system is described,nwhich allows the analysis of gas composition inside the RTP chamber withnatmospheric pressure ionization mass spectrometry (APIMS). Sampling isncontrolled with no valve operation and high dilution of the sample gasnflow can be achieved while maintaining a short sample transfer time. Itnis shown how gas flows can be optimized to improve the sensitivity andnresolution of TDS spectra. The RTP-APIMS setup was used in a study of Hn2O absorption by low dielectric constant fluorinated silicanglass (FSG) films, helping to develop a cap that reduced H2Onabsorption upon storage by a factor of 60. NH3 is shown tondesorb from FSG and SiO2 films deposited by plasma-enhancednchemical vapor deposition (PECVD), which may be of concern for thenreliability of integrated circuits