Characterization of 28Si+ and 40Ar+ ion-implanted epitaxial ReSi2 films on an n-Si(100) substrate

Abstract

The structural and electrical characteristics of 300 keV Si+ or 380 keV Ar+ ion-implanted epitaxial ReSi2 films grown on an n-Si(100) substrate have been studied by using 2 MeV 4He+ ion backscattering spectrometry, x-ray diffraction, high-resolution transmission electron microscopy, and electrical measurement. Ion implantation causes static disorder in the film, which overlap and grow to become an amorphous layer. The threshold dose for amorphizing the ReSi2 film is ∼5×1014/cm2 for 28Si+ and ∼1×1014/cm2 for 40Ar+. Although the resistivity of the implanted ReSi2 film decreases when the degree of disorder (or the implantation dose) is increased, the resistivity reaches a minimum value at a dose of ∼1×1015/cm2 for Si+ or ∼5×1014/cm2 for Ar+. The 28Si+-implanted amorphous ReSi2 films recovered original epitaxy after thermal annealing at 700 °C for 30 min in vacuum, as do the partly amorphized ReSi2 films by 40Ar+ implantation. On the other hand, those films fully amorphized by 40Ar+ implantation (dose≥1×1014/cm2) did not recover after thermal annealing, even when exposed to a temperature as high as 1000 °C for 30 min.