Physicochemical properties of the surface and near-surface region of epitaxial n-GaAs layers modified by atomic hydrogen

Changes in the static electrical parameters of the Au-GaAs Schottky barrier s in the (n-n(+))-GaAs structures treated with atomic hydrogen are closely related to modification of the chemical properties of the surface layers in these structures, including changes in the rate of n-GaAs etching in a DMF -monoethanol amine (1:3) solution, in the electrochemical deposition rate a nd the structure of the resulting Au layer, and in the degree of passivatio n of linear defects emerging on the surface. The unprotected surface of epi taxial n-GaAs(100) layer exhibited virtually no etch pits upon the treatmen t in atomic hydrogen at 100 degrees C. For n-GaAs protected with a 50-Angst rom-thick SiO2 film, a drop in the etching rate and a considerable decrease in the number of etch pits, as well as a decrease in the thickness of elec trochemically deposited gold layer and a change in is structure, were obser ved for the samples treated in atomic hydrogen at all temperatures in the r ange studied (100-400 degrees C). (C) 2000 MAIK "Nauka/Interperiodica".