Molecular dynamics and experimental characterization of amorphization in silicon substrates during aerosol deposition

This study explores the amorphization mechanisms in silicon (Si) wafer during aerosol deposition (AD) of alumina particles. Utilizing molecular dynamics (MD) simulations and experimental methods, the research investigates the high-velocity impact process and resulting microstructural changes in Si. Experimental observations using TEM and EDS confirm the presence of a thick amorphous Si layer directly beneath the alumina coating. The MD simulations of alumina aggregate impact on an initially flat, defect-free Si surface reveal the formation of amorphous bands initiating at the surface and propagating along maximum shear stress directions into the bulk. Lattice defects such as dislocations and stacking faults are not involved in the onset of amorphization but may act as precursors for further amorphization due to successive impacts.