Difference in the structures on highly B-doped Si(111) surfaces by heating treatments

The 3×3 structure was prepared by annealing highly B doped Si. We prepared two types of surfaces: (A) by annealing at 900°C for 10 min, and (B) by flashing at 1180°C. Both surfaces were observed using scanning tunneling microscopy, and the concentration of B was estimated at 95% for surface (A) and 70% for surface (B), respectively. The RHEED rocking curve from surface (A) suggests that the position of B in an S5 site is slightly higher (0.16 إ) than a model proposed by Lyo et al. [I.-W. Lyo et al., Phys. Rev. Lett. 63 (1989) 1261] by comparison with a result of dynamical calculation. The main feature of the rocking curve from surface (B) can be explained by a model structure including the other site without substitution of B for Si.