Solid Phase Epitaxial Regrowth of Amorphous Layers in Silicon Created by Low Energy Phosphorous Implantation: A Medium Energy Ion Scattering Study

Abstract

Medium energy ion scattering (MEIS) has been used to study the kinetics of solid phase epitaxial regrowth (SPEG) of ultrathin amorphous layers created by room temperature implantation of 5 keV energy phosphorus ions into Si(1 0 0). P ion fluences ranged from 5e14 cm-2 up to 1e16 cm-2, the associated a-Si thicknesses from 9.2 nm to 20 nm. Regrowth was driven by rapid thermal annealing for anneal temperatures 425 °C ≤ TA ≤ 600 °C and for times up to 2500 s. The Si(P) regrowth velocities exceed that of the intrinsic Si SPEG rate by an order of magnitude. Regrowth in the near surface is approximately 1.7 times slower than in the bulk. In Si implanted to high P fluence, Φ ≥ 5e15 cm-2, regrowth is severely retarded when the recrystallization front intercepts P concentrations in excess of ∼1e21 cm-3. Show more