EFFECTS OF MEV ION IRRADIATION OF THIN CUBIC BORON-NITRIDE FILMS

Adherent baron nitride thin films with a high cubic phase content (up to about 90%) were synthesized over large areas by means of ion assist ed evaporation. Besides the well known superior properties of cubic ba ron nitride (c-BN) nearly nothing is known about the behavior of c-BN under MeV ion irradiation where the ions penetrate through the thin fi lm and come to rest far away in the substrate. Therefore, exploratory MeV ion implantation experiments into as-deposited c-BN rich films wer e conducted at room temperature. Ions with different masses were chose n to study the effect of the nuclear and electronic stopping processes on the highly cubic BN films. Furthermore the influence of various io n doses (3.5x10(13)-2.0x10(17) ions/cm(2)) on the cubic structure was investigated. To get an insight into the effects of the different post -deposition treatments, the as-deposited and ion implanted films were analyzed by Fourier transformed infrared spectroscopy, Rutherford back scattering, x-ray diffraction, and Auger electron spectroscopy. Depend ing on the ion dose, the heavy Xe ion implantation results in four dif ferent regimes for the resulting material. The implantation induced th e total number of displacements per unit volume as an essential measur e of the effect of the postdeposition treatment. Depending on the tota l number of displacements per unit volume the cubic BN structure can b e transformed into a hexagonal BN dominated network. (C) 1998 American Institute of Physics.