Atomic‐Scale Capture the Kinetics of Oxygen Precipitates in Crystalline Silicon

Understanding the kinetics of defects and solid‐state transformations within crystalline silicon is paramount for guaranteeing the reliability of silicon‐based integrated circuits. Oxygen impurity within crystalline silicon commonly undergoes complex evolutions during state‐of‐the‐art growth and advanced manufacturing processes, resulting in performance‐degrading oxygen precipitates (OPs) and associated oxygen‐related defects. Despite decades of research, the comprehensive atomic‐scale kinetic pathways of oxygen have remained elusive. Therefore, we directly visualize the oxygen kinetics in crystalline silicon by capturing its precipitation and dissolution behaviors at atomic scale, employing atomic‐resolved scanning transmission electron microscopy (STEM). The facet‐dominated OP growth is revealed through capturing the morphological transformation from nascent irregular clusters to well‐defined polyhedral structures. These polyhedral structures are predominantly terminated by energetically favorable (100) and (111) facets at the OP/Si interfaces, synergistically complemented by theory calculations. Quantitative and atomic‐scale strain maps are further provided at the OP edge (tensile strain) and surrounding transition region (compressive strain). In conjunction with in situ heating STEM, the dynamic OP dissolution process is directly observed, demonstrating a dual‐synergistic mechanism involving concurrent edge epitaxy and internal reconstruction, both driven by the oxygen counter‐diffusion. Our findings provide a theoretical foundation for defect engineering and offer valuable insights for optimizing the annealing processes and mitigating performance fluctuations of Si‐based ICdevices.