TXRF calibration samples fabricated by atomic layer deposition (ALD) and photolithography

Abstract

In this contribution, an innovative fabrication process for metallic trace element reference samples is introduced. These can be used to calibrate and maintain tools for the detection of those metallic trace elements like the total reflection x-ray fluorescence (TXRF) method which are used in semiconductor and microsystem fabrication facilities. The fabrication process is based on the complete covering of silicon wafers with atomic layer deposition (ALD) and structuring of this layer using photolithography. ALD is the deposition process of choice, since the self limiting behavior is well suited to cover the whole wafer with an minimal amount of material. Samples with metal amounts as low as 1010 atoms per cm2 could be achieved with that process.