Analysis of a Sputtered Si Surface for Ar Sputter Gas Supply Purity Monitoring

TL;DR

This paper presents a new method for monitoring the purity of Ar sputter gas during depth profiling by measuring surface contamination levels of Ar, C, N, and O on a silicon sample over a decade.

Contribution

It introduces a novel measurement procedure to assess sputter gas purity and contamination levels, improving accuracy in depth profiling analyses.

Findings

Surface contamination levels correlate with sputter gas purity.

Long-term data shows stability and reliability of the measurement method.

Monitoring can prevent misleading depth profile results.

Abstract

For sputter depth profiling often sample erosion by Ar+ ions is used. Only a high purity of the sputter gas and a low contamination level of the ion gun avoids misleading depth profile measurements results. Here a new measurement procedure is presented, which monitors these parameters. A Si sample is sputtered inside the instrument and then the surface concentration of the elements Ar, C, N and O is measured. Results of such measurements of an XPS microprobe PHI Quantum 2000, which were recorded over a period of 10 years, are presented.