The pattern formation during ion bombardment of Cu(001) investigated with helium atom beam scattering

The bombardment of Cu(001) with Ar ions at substrate temperatures between 100 K and ca 300 K leads to the formation of pyramid-like void structures with specific angle selections between the base and the sides of the pyramids. This structure is largely ''reciprocal'' to the morphology produced in the growth of Cu on Cu(001) in the sense that adatom pyramids are replaced by vacancy pyramids. Their common origin lies most likely in an asymmetry in horizontal and vertical atom mobility due to the presence of the Schwobel-Ehrlich barrier. (C) 1997 Elsevier Science B.V.