Spectroscopic Ellipsometry as a Tool for Damage Profiling in Very Shallow Implanted Silicon

Abstract

AbstractSummary: Ion implantation is still one of the key steps in Si integrated circuit technology. Spectroscopic Ellipsometry (SE) detects the defects created in the implanted Si. The successful application of SE for damage profiling depends on the quality of the algorithm used for evaluating the damage profile from SE data. In this work, we present retrieved SE damage depth profiles by our previously published algorithm in the as‐implanted Si with very low energies Ge+ ions‐ from 2 keV to 20 keV and 1 keV B+ ions (1 × 1015 cm−2). The comparisons of the SE retrieved damage depth profiles with experimental atomic concentration depth profiles, or simulated by the state‐of‐the‐art computer ATHENA code of Silvaco TCAD suits were made. The functional relation was obtained by proper fitting of measured by SE a/c depths, and the depths named “ends of damage” with the experimental or simulated ions concentration depth profiles. For reasons not understood, the damage profile of 5 keV Ge+ in c‐Si is smoother in shape beyond the a/c depth, with a longer tail.The damage profiles measured by SE for 5 keV Ge+ in c‐Si with two different doses: curve 1 ‐ for 6 × 1013 cm−2 and curve 2 ‐ for 1 × 1015 cm−2. Curve 3 ‐ presents the damage profile simulated by ATHENA for Ge+ ions with 5 keV; 1 × 1015 cm−2.imageThe damage profiles measured by SE for 5 keV Ge+ in c‐Si with two different doses: curve 1 ‐ for 6 × 1013 cm−2 and curve 2 ‐ for 1 × 1015 cm−2. Curve 3 ‐ presents the damage profile simulated by ATHENA for Ge+ ions with 5 keV; 1 × 1015 cm−2.