SUMMARY OF SCHOTTKY-BARRIER HEIGHT DATA ON EPITAXIALLY GROWN N-GAAS AND P-GAAS

The Schottky barrier height values, as determined by the current-volta ge and capacitance-voltage techniques, of 43 metals which were fabrica ted by following the same cleaning procedure and using the same high-q uality organometallic vapour phase epitaxially (OMVPE) grown (100) n-t ype GaAs material and 13 metals on molecular beam epitaxially grown (M BE) p-GaAs, are presented. Of all the metals involved in this study, G a had the lowest mean Schottky barrier height of about 0.60 eV on n-Ga As and the highest on p-GaAs of 0.83 eV. Cu, Ag, Pt and Sb had the hig hest barrier heights of about 1 eV on n-GaAs. It was found that there exists no linear relationship between Schottky barrier height and meta l work function as is suggested by the Schottky-Mott theory, if all 43 metals are taken into account. Similar results were obtained if the m etal work function was replaced by the Pauling or Miedema electronegat ivities. In contrast with this, if only a selected group of metals is chosen and more specifically those with the higher melting points whic h were deposited by means of an electron gun, an approximately linear tendency does exist between Schottky barrier height and metal work fun ction. From this linear dependency, the density of states was determin ed to be about 6 x 10(13)/eV per cm(2) and the average pinning positio n of the Fermi level as 0.55 eV below the conduction band. (C) 1998 El sevier Science S.A. All rights reserved.