The crystal defect structure of InP following scratching with an atomic force microscope tip was studied using transmission electron microscopy. The (100) surfaces of InP single crystals were scratched along <100> and <110> directions using an atomic force microscope diamond tip under applied normal forces ranging from 7 to 120μN. For a given applied force, deeper plastic flow was observed in the <110> case than in the <100> case. Under increasing applied forces, plastic flow was first observed at 15μN for <110>, and at 30μN for <100>. The crystal deformation during a scratch event was observed to consist of three stages: (a) surface conformation to the shape of the atomic force microscope tip during the early stages of the process, and it was associated with slip at the nanoscale with the formation of an inverted triangular region with high dislocation density; followed by (b), a sudden displacement (pop-in) that signals the beginning of downward slip at the bulk scale; and (c), for sufficiently large forces, recovery of the bulk elastic strain by upward slip (pop-up). The <110> scratch direction was aligned along the {111} slip planes, and yields at lower applied forces than in the <100> case. Dislocations introduced by scratching were mostly screw type, as determined by series of g.b analysis.

Microstructure of Nanoscratched Semiconductors. J.Y.Huang, F.A.Ponce, P.G.Caldas, C.M.Almeida, R.Prioli: Journal of Physics: Conference Series, 2011, 326[1], 012061