Dwell-time related effects in focused ion beam synthesis of cobalt disilicide

The influence of the high current density of a focused ion beam on the ion beam synthesis of CoSi2 layers has been investigated. After 35 keV Co+ or 7 0 keV Co2+ implantation into a heated Si(111) substrate and subsequent anne aling, the layers have been investigated by scanning electron microscopy an d Rutherford backscattering spectroscopy (RBS). It is shown that the mode o f beam scanning influences the CoSi2 layer formation significantly. At a gi ven substrate temperature, a sufficient low dwell time is required to obtai n a continuous layer rather than a laterally disrupted structure. With incr easing target temperature, the dwell-time window becomes less restricted. T he results are discussed in terms of damaging and dynamic annealing of the silicon crystal. RBS channeling investigations demonstrate that continuous or disrupted CoSi2 layers are formed when the substrate remains crystalline or becomes amorphous, respectively. (C) 2000 American Institute of Physics . [S0021-8979(00)03901-3].