Nickel film orientation change by nitrogen ion bombardment during deposition

Abstract

The influence of nitrogen ion bombardment during e-beam triode ion plating of nickel on the microstructure and film orientation has been investigated. The deposition variables explored were the ion current density and deposition rate while the substrate temperature (ambient), partial pressure of nitrogen (3 x 10(-4) Torr) and substrate bias potential (4.5kV) were constant. The orientation and growth morphology change for films about 1 mu m thick were determined by XRD, SEM and STM method. The preferred orientation changes from (111) to nearly complete (200) as a function of ion to atom arrival ratio (IAR), and was independent of the substrate type (amorphous or monocrystalline). The ion beam bombardment of films after deposition enables the in depth determination of the nickel texture change during growth. For the highest IAR value the complete (200) texture was achieved at the beginning of deposition. The surface morphology (STM) and preferred orientation changes were correlated with ion to atom flux ratio and discussed on the basis of lowering the overall energy of the film. (C) 1997 Elsevier Science Ltd.