Linear arrays of InAs nanocrystals have been produced by metalorganic vapor phase epitaxy on scratches performed with an atomic force microscope tip along specific crystallographic directions of an (100) InP wafer. Scratches along 〈 110 〉 generate highly mobile defects that extend far from the scratch region along easy-glide directions. On the other hand, 〈 100 〉 scratches result in highly-localized plastic deformation, hardening, and possibly frictional heating. In both cases, growth of nanocrystals was observed only on the scratched areas. Random nucleation of nanocrystals is observed along 〈 110 〉 scratches, while linearly ordered growth occur along 〈 100 〉 scratches. We attribute these observations to the delocalized nature of the dislocations in the 〈 110 〉 case, giving the appearance of random nucleation, while highly localized crystal defects along the 〈 100 〉 scratch lines act as nucleation sites for the growth of linear arrays of nanocrystals. © 2010 American Institute of Physics.