Deformation Mechanism of Indium Phosphide Wafers by Indenter Shape in Nanoindentation

Molecular dynamics (MD) simulations of nanoindentation were employed to investigate the mechanical properties and elastoplastic deformation mechanisms of single-crystal indium phosphide (B3-InP) wafers oriented along the [001] crystal direction. The study examines the evolution of dislocation propagation, atomic motion, stress distribution, and strain evolution under varying indenter geometries, including Ball, Berkovich, and Vickers indenters. The results reveal that as the indentation depth increases, the pop-in phenomenon occurs first with the Ball indenter and last with the Vickers indenter, suggesting that the pop-in phenomenon is more pronounced and plastic deformation initiates more rapidly with indenters exhibiting more homogeneous stress distributions compared to those with concentrated stress distributions. Regardless of indenter shape, generated dislocations primarily consist of Shockley dislocations, with a smaller presence of perfect dislocations. These dislocations exhibit atomic displacement and slip along the ⟨110⟩ crystalline direction.