A Review of Standardization Issues for Total Reflection X-Ray Fluorescence and Vapor Phase Decomposition/Total Reflection X-Ray Fluorescence

Abstract

Total reflection X-ray fluorescence (TXRF) and vapor phase decomposition (VPD) followed by TXRF have become widespread methods for measuring surface metal contamination on silicon wafers. For quantification, TXRF and VPD/TXRF require reference samples. Since the approaches to making and using these reference samples have significantly varied among TXRF manufacturers and users worldwide, there exists some confusion about the quantification of TXRF and VPD/TXRF. This paper summarizes the basic issues behind TXRF and VPD/TXRF quantification using reference samples.

Saturation effects in TXRF on micro-droplet residue samples

“…Droplet residues standards were prepared by the micro-droplet deposition method. 22 Standard multi-element solutions were prepared in volumetric flasks (polyethylene) by dilution of ICP-MS calibration standards (1000 mg ml À1 , nitrate salts, Merck) using ultra-pure water. All solutions were acidified with HNO 3 (2 vol% of 70 w%, Ultrex, Baker) to prevent adsorption on the container walls.…”

A Procedure for the Improvement in the Determination of a TXRF Spectrometer Sensitivity Curve

“…12 It also avoids validation studies between different techniques in order to assure the quality of TXRF results. A work has indicated very close agreement between vendor-certified values on TXRF reference calibration standards and the results from an ion beam technique heavy ion backscattering spectrometry (HIBS) 13 which does not require standards for accurate analysis. Other inter-comparison studies have focused on the combination of VPD-DC with TXRF, more specifically on the accuracy of TXRF in the analysis of the micro-droplet residues.…”

Remediation for TXRF saturation effects on microdroplet residues from preconcentration methods on semiconductor wafers

“…Droplet residues standards were prepared by the microdroplet deposition method. 11 Standard multi-element solutions were prepared by dilution of ICP-MS calibration standards (1000 ppm, nitrate salts, Merck). All solutions were acidified with HNO 3 (70%, Ultrex, Baker).…”