FORMATION OF SILVER SINGLE-CRYSTAL THIN-FILMS BY ARGON ION-IMPLANTATION

A silver single crystalline thin film with a thickness of 150 nm was s uccessfully formed on a NaCl substrate by argon ion implantation. The transmission electron microscopy bright field (TEM BF) image shows tha t there are many oriented twins but no grain boundaries in the film. W hile maintaining the same implantation conditions with respect to ion species, ion energy, beam current density and dose, grain growth is su bstantial in films with a thickness of 50 nm on a NaCl substrate; grai n growth in films with a thickness of 100 nm deposited on an amorphous carbon substrate is minimal. The presence of implanted Ar in a Ag fil m was detected by Auger electron spectroscopy (AES); it was found that most of the implanted Ar atoms had escaped the film. The driving forc e for grain growth in thin films is discussed. The results suggest tha t ion-beam-induced silver single crystalline thin film formation may b e due to above-critical-state excitation resulting in a rapid grain an nexing process.