Vapor phase decomposition–droplet collection–total reflection X-ray fluorescence spectrometry for metallic contamination analysis on Ge wafers

Automated nanoliter solution deposition for total reflection X-ray fluorescence analysis of semiconductor samples

“…As the TXRF is being used to characterize the new films being introduced into the semiconductor process line and to monitor for cross contamination from these new materials [14][15][16][17][18], nanoliter depositions can be used with TXRF to improve upon the characterization process. Fig.…”

Trends in total reflection X-ray fluorescence spectrometry for metallic contamination control in semiconductor nanotechnology

“…Whereas before only Si and SiO 2 wafers were measured, now a whole range of materials as wafers or layers have been reported in research and development applications: silicon nitride [102,103], siliconon-insulator (SOI) [104], Ge [105,106], GaAs [107,108], HfO 2 [109][110][111], Al 2 O 3 [110,111], Ta 2 O 5 [112], polymer layers [113] and other unpublished materials. Both procedures for Direct-TXRF and VPD-DC-TXRF have been reported.…”

“…A first concern is that, in order not to have droplet loss during scanning in the droplet collection step, the collection liquid must exhibit a high contact angle (roughly >50°) on the substrate. For Ge substrates for example, the substrate after VPD exposure (contact angles <10°) is not sufficiently hydrophobic to allow scanning using dilute aqueous solutions [106]. Concentrated HCl or HBr solutions however showed higher contact angles enabling the scanning process.…”

“…For silicon nitride layers for example, this has been realized by an evaporation of the reaction salt after the VPD process [102]. In the case of Ge wafer samples, removal can be obtained selectively over the analyte by evaporation of GeCl 4 during the droplet drying process after the collection step [106]. From these examples it is clear that the procedures must be adapted closely related to the wetting properties and the feasibility for matrix removal.…”