NANOMETER-SCALE DEPOSITION OF GA ON HF-TREATED SI(111) SURFACES THROUGH THE DECOMPOSITION OF TRIETHYGALLIUM BY SCANNING-TUNNELING-MICROSCOPY

Ga dots on a nanometer scale were deposited using a scanning tunneling microscope (STM) through the decomposition of triethylgallium (TEGa) adsorhed on HF-treated Si(111) surfaces. The deposition of Ga dots of 2-13 nm in diameter was achieved by applying a negative voltage pulse to the sample, while no deposition was observed when a positive voltage pulse was applied. The conditions for Ga deposition were systematically investigated by varying the gap conductance, pulse height and pulse width. A tentative model for the mechanism of Ga deposition is proposed, in which TEGa molecules are decomposed by the electric field between the tip and the sample.