Deformation Mechanism of Indium Phosphide Wafers by Spherical Indenter Radius in Nanoindentation Based on Molecular Dynamics Simulation

Abstract

Using the LAMMPS software, a nanoindentation model was developed via molecular dynamics (MD) to investigate the deformation behaviour of single-crystal zinc blende-structured indium phosphide (B3-InP) wafers along the [001] crystal orientation. The study examined the indentation process with different spherical indenter radii (45 Å, 50 Å, 55 Å, 60 Å). It analysed the effect of the indenter radius on dislocation propagation, atomic displacement, shear strain and phase transformation in B3-InP wafers during nanoindentation. The results show that the plastic deformation of B3-InP wafers is attributed to the dislocation propagation, phase transition and amorphous phase transition. The critical load for the elastic-plastic transition increased with increasing indenter radius. Almost all dislocations in the indentation process were 1/6<112> Shockley incomplete dislocations, 1/2<110> perfect dislocations and some unrecognisable dislocation types. The magnitude and range of atomic displacements and shear strain distribution increased with increasing indenter radius, which promotes the dislocation nucleation and propagation in the slip system and exacerbates the plastic deformation of B3-InP wafers. Increasing the indenter radius also promotes the phase transition of B3-InP wafers to lead-zinicite structure indium phosphide (B1-InP) wafers and enhances the amorphisation of B3-InP in the deformation layer. These results provide significant insights into the mechanical behaviour of B3-InP, particularly its response to nanoindentation, thereby contributing valuable knowledge for applications involving the precision machining of semiconductor materials.