Round-Robin Test of Medium-Energy Ion Scattering for Quantitative Depth Profiling of Ultrathin HfO₂/SiO₂/Si Films

Abstract

Medium energy ion scattering (MEIS) has been used for quantitative depth profiling of ultrathin films with single atomic layer resolution. To assure the consistency of the MEIS analysis, an international round-robin test with nominally 1, 3, 5, and 7 nm thick HfO₂ films was conducted among 12 institutions. The standard deviations were 5.3% for the composition, 15.3% for the thickness, and 13.3% for the Hf content by using stopping and range of ions in matter (SRIM) 95, and they were improved to 7.3%, 4.5%, and 7.0% by using refitted electronic stopping powers based on the experimental data. This study suggests that correct electronic stopping powers are critical for quantitative MEIS analysis.