Surface Reactions During the Deposition of Ge from Chemical Sources on Ge(100)-(2×1)

Abstract

AbstractThe adsorption and decomposition of diethylgermane, triethylgermane, and digermane on the Ge(100) surface are investigated with the intent of elucidating the surface processes leading to the deposition of epitaxial Ge films. Room temperature adsorption of diethylgermane or triethylgermane leads to the formation of surface germanium hydrides and ethyl groups. The ethyl groups decompose at higher temperatures and form ethylene via a β-hydride elimination reaction. Isotopic labeling experiments are used to confirm this reaction step. This is in contrast to the Si(100) surface where both α- and β-hydride elimination is observed for the decomposition of surface ethyl groups. The adsorption and reaction of digermane with the Ge surface is also determined to help provide a comparison with the ethylgermanes. Low energy electron diffraction is used to evaluate the quality of the deposited germanium films.