Method for the alignment of samples and the attainment of ultra-high-resolution depth profiles in Auger electron spectroscopy

✍ Scribed by C. P. Hunt; M. P. Seah

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 627 KB
• Volume: 15
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/sia.740150404

✦ Synopsis

Abstract

The need to align the electron beam, the electron spectrometer axis and the ion beam all at the same point on the sample surface in sputter‐depth profiling using Auger electron spectroscopy is crucial to the attainment of efficient high‐resolution profiles. In this study we develop a method that allows these axes to be set to ±25 μm in concentric hemispherical analyser systems. Then, using the coincidence of the electron beam and spectrometer axes, samples may be repositioned repeatedly to ±25 μm and the point of analysis on the sample to within ±40 μm of the centre of the ion‐sputtered crater. The method is illustrated in the characterization of a second batch of tantalum pentoxide on tantalum reference material. New resolutions of 1.51 and 1.60 nm are achieved for the 31.1 and 95.8 nm thick oxides, respectively, when using the standard conditions of 2 keV argon ions and monitoring the oxygen Auger electrons. If the ion energy is reduced to 1.5 keV and the tantalum low‐energy peaks are used, the resolution for the 95.8 nm oxide may be reduced to 0.82 nm.