Structural damage induced by Ga+ focused ion beam implantation in (001) Si

Abstract

Ga+ focused ion beam (FIB) implantation in (001) Si was conducted in our JEOL JIBL-104UHV FIB system. Ga+ ions with energy of 100 kV were implanted into silicon at doses from 1×1014 to 1×1016 /cm2. The current and current density of the Ga+ FIB are 20 pA and 1 A/cm2, respectively. We have made patterns consisting of single-pixel lines with various spacings and rectangular areas of different sizes. The critical dose to form a continuous amorphous region in rectangle-scanned samples is less than 5×1014 /cm2. The samples were annealed either in vacuum or a rapid thermal annealing furnace at 550–800 °C for 1/2 h and 60 s, respectively. Both cross-sectional and plan-view transmission electron microscopy were conducted to investigate the lattice disorder and residual defects in as-implanted and post-implantation annealed samples. After thermal annealing, dislocation lines and loops were observed along the line direction in line-scanned samples. In rectangle-scanned samples, dislocation lines and loops near the original amorphous/crystalline (a/c) interface, as well as edge defects along the edge of the rectangle were found.