Influence of metal interlayers on Schottky barrier formation for Au/ZnSe (100) and Al/ZnSe (100)

Schottky barrier formation for Al/ZnSe (100) and Au/ZnSe (100) was studied using photoelectron spectroscopy. The initial Fermi level position for sputter-annealed ZnSe (100) surfaces was 2.05 eV above the valence-band maximum (VBM). The final Fermi level position, established after the deposition of several monolayers of metal adatoms, was very different for Al (2.17 eV) and Au (1.25 eV, relative to the VBM). The deposition of Au interlayers for Al/Au/ZnSe and Al interlayers for Au/Al/ZnSe showed that it is possible to ‘‘tune’’ the Schottky barrier height between these extremes by choosing interlayers of definite thickness.