In this work, we introduce a new method that correlates changes in the adhesion and the electrical stress induced defects at the nanometer length scale in dielectric thin films using a conductive atomic force microscope (CAFM). Taking a simple case of silicon dioxide (SiO2), we demonstrate that adhesion at the CAFM tip-oxide contact increases after electrical stress. We also present evidence showing that the polarity dependence of the post-breakdown adhesion is primarily due to the interplay of the CAFM tip with the chemical/ionic bonding and with the electrostatically-charged stress-induced defects (i.e., oxygen ions and vacancies). This new approach can be potentially used to infer the trapped charge densities at the nanometer length scales in dielectrics.
Bibliographical noteKAUST Repository Item: Exported on 2021-06-30
Acknowledgements: A. Ranjan would like to acknowledge the Presidents’ Graduate Fellowship, Ministry of Education (MOE) for his PhD studies. This research work has been primarily funded by Kwan Im Thong Hood Cho Temple Chair Professorship grant at Singapore University of Technology and Design (SUTD). Fruitful discussions with Alex Shluger and Kamal Patel (both from UCL) are gratefully acknowledged. Authors thank Xixiang Zhang and Chenhui Zhang (both from KAUST) for technical discussions. N. Raghavan would like to acknowledge the conference travel support from the A*STAR Programmatic Grant - BRENAIC (A18A5b0056) project. N. Raghavan would additionally like to acknowledge the support from MOE Academic Research Funds (MOE AcRF Tier-1 (SUTDT12017005) and Tier-2 (MOE2017-T2-1-115)).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.