Exploring dielectric properties in atomistic models of amorphous boron nitride

Galvani, Thomas [Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain] Hamze, Ali K [Advanced Materials Lab, Samsung Semiconductor Inc., Cambridge, MA 02138, United States of America] Caputo, Laura [UCL] Kaya, Onurcan [Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain] Dubois, Simon M-M [UCL] Colombo, Luigi [CNMC, LLC, Dallas, TX 75248, United States of America] Nguyen, Viet-Hung [UCL] Shin, Yongwoo [Advanced Materials Lab, Samsung Semiconductor Inc., Cambridge, MA 02138, United States of America] Shin, Hyeon-Jin [Department of Semiconductor Engineering, School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea] Charlier, Jean-Christophe [UCL] Roche, Stephan [Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain] et al.[show all]

We report a theoretical study of dielectric properties of models of amorphous Boron Nitride, using interatomic potentials generated by machine learning. We first perform first-principles simulations on small (about 100 atoms in the periodic cell) sample sizes to explore the emergence of mid-gap states and its correlation with structural features. Next, by using a simplified tight-binding electronic model, we analyse the dielectric functions for complex three dimensional models (containing about 10.000 atoms) embedding varying concentrations of sp1, sp2 and sp3 bonds between B and N atoms. Within the limits of these methodologies, the resulting value of the zero-frequency dielectric constant is shown to be influenced by the population density of such mid-gap states and their localization characteristics. We observe nontrivial correlations between the structure-induced electronic fluctuations and the resulting dielectric constant values. Our findings are however just a first step in the quest of accessing fully accurate dielectric properties of as-grown amorphous BN of relevance for interconnect technologies and beyond.