Low temperature formation of Si(1 1 1)-(2n+1) × (2n+1) surface reconstructions

Scanning tunneling microscopy was used to study the surface morphology changes of the H-terminated Si(1 1 1) surface during Ag deposition at elevated temperatures. Flat H-terminated Si(1 1 1) surfaces were prepared by NH4F etching. Domains of various dimer-adatom-stacking-fault superstructures, such as 3×3, 5×5, 7×7, and 9×9 were observed on the Si(1 1 1) surface after hot deposition of 1 ML Ag at 550 °C. This phenomenon was compared with hydrogen thermal desorption experiments, which did not show the formation of metastable surface superstructures at temperatures near 550 °C. All metastable superstructures obtained after hot Ag deposition at 550 °C were found to convert into the 7×7 reconstruction after annealing at 600 °C.