Nanoscale dislocation patterning by scratching in an atomic force microscope

Abstract

The nature of nanoscratching as a lithographic technique for site-selective generation of dislocations is investigated for use in the growth of nanostructures. Linear arrays of dislocations have been selectively introduced into (001) indium phosphide crystals by dragging a diamond tip in an atomic force microscope. The nature of plastic deformation is found to depend on the scratch direction. For ⟨110⟩ directions, anisotropic butterflylike structures with mostly screw dislocations indicate rotational motion in the vicinity of the advancing tip. For ⟨100⟩ directions, the dislocations do not propagate far from the surface, possibly due to interlocking between dislocations on different slip planes, with a surface morphology suggesting melting of the near surface region by frictional heat. These results indicate that growth of nanostructures should be highly dependent on the direction of the nanoscratch.