Silicon nitride crystallization study via molecular dynamics and the Ultra-Fast 3-body (UF3) machine-learned interatomic potential

Amorphous silicon nitride (SiN) is an insulating layer material in microelectronics devices which acts as an ion diffusion barrier. Under high-temperature (>1300K) annealing conditions, experiments have demonstrated unexpected crystallization to alpha Si₃N₄. We employ molecular dynamics (MD) methods to understand the primary drivers for this crystal growth phenomenon using the Ultra-Fast 3-body (UF3) machine-learned interatomic potential.  UF3 is an accurate, efficient, and interpretable potential framework for training from quantum calculations. We present an analysis of amorphous silicon nitride structure and dynamic properties of the amorphous to crystalline transition. These results are compared and contrasted with several established empirical interatomic potentials, as well as with experimental measurements. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525