Ga-induced restructuring of Si(5 5 12) − 2 × 1 reconstructed surface at room temperature

Abstract

Motivated by the need to form 1D-nanostructured dopants on silicon surfaces, we have attempted to grow Ga on the high index Si(5 5 12) surface which has a highly trenched (1D) morphology. The evolution of the interface with Ga adsorption in the monolayer regime has been probed by in situ AES, LEED and EELS. Controlling the kinetics by changing the Ga flux rates shows an interesting difference in the 1.0 to 1.5 ML region. The low flux rate (0.03 ML/minute) results in a Frank van der Merwe (layer by layer) growth mode up to 2 ML, while the higher flux rate (0.1 ML/minute) shows a transient island formation after the completion of 1 ML. The low rate shows the formation of 2 × (3 3 7) and (2 2 5) superstructures, while only the 2 × (3 3 7) is observed in a wide coverage range for the higher rate. The results demonstrate the ability to kinetically control the surface phases with different electronic properties of this technologically important interface.