The damaged layer induced in a silicon crystal by surface scratching at room temperature under a light load was found, by transmission electron microscopy, to be a small amorphous region surrounded by a dislocated crystalline region. No dent was detected on the surface and no crack was developed around the scratch. The amorphous region seems to be formed by phase transformation and not as the result of heavy plastic deformation of the crystal. The amorphous region was recrystallized to a dislocated crystalline region by annealing of the crystal at 600 °C.

• Received 31 March 1992

DOI:https://doi.org/10.1103/PhysRevLett.69.320