Direct observation of intra-grain defect formation during local solid-phase epitaxy.

Despite relentless efforts to improve fabrication processes, the achievement of a defect-free polycrystalline film (poly-film) through solid-phase crystallization (SPC) remains challenging, as evidenced by structural analyses. Understanding the dynamics of intermediate processes, including the precursor phenomena, is crucial for developing strategies to suppress defect formation. In this study, we directly observed elementary processes during crystal growth at local interfaces between crystalline Si (c-Si) grains and uncrystallized amorphous Si (a-Si) regions within a Si thin film using in situ high-resolution transmission electron microscopy.