Silicon protrusions with caps containing precipitates of iron silicides fabricated via liquid-phase epitaxy under a temperature distribution with a local maximum caused by applied tensile stress

Abstract

Silicon (Si) protrusions containing iron (Fe) silicides were fabricated in a process of surface melting and solidifying. Si(001) and Si(111) pieces with Fe depositions were heated at 1250 °C under a local tensile stress of ∼2 GPa. This surface stress locally increased the surface temperature through DC heating. The Si atoms in the melting surface region with Fe flowed to the lower temperature region via electromigration, and they turned into a single-crystal Si protrusion with caps at its top, including the single-crystal Fe silicide precipitates. The sizes of the protrusion, the caps, and the precipitates depended on the amount of Fe deposition. Additional small side protrusions were found on the sides of the protrusions on the Si(001) surface but not on the Si(111) surface. These results indicate that the surface fine structures and composition can be controlled by changing the surface crystal orientation and deposition metal without lithographic approaches.