Effect of oxygen adsorption on ion beam induced recrystallization of copper films

Oxygen adsorption effects on the crystallization of copper films under the irradiation of 2 MeV Ar+ ions were investigated by using two types of substrates, one of which was the oxygen saturated SrTiO3 (100) and the other was the oxygen deficient SrTiO3 (100). As-deposited copper films consisted of fine crystals with random orientation. The copper crystals on both types of the substrates were grown without epitaxial relation when ion-irradiated under oxygen atmosphere. The epitaxial growth of copper films was achieved on the oxygen saturated substrate with the sequential procedure of oxygen adsorption and ion irradiation. The epitaxial relationship between the film and the substrate was determined Cu (100)parallel to SrTiO3 (100) and Cu [001]parallel to SrTiO3 [001]. The growth mechanism was discussed from the viewpoint of the surface reaction of oxygen with copper.