SILICON-INDUCED LOCAL INTERFACE DIPOLE IN AL GAAS(001) SCHOTTKY DIODES

Al/Si/GaAs(001) diode structures grown by molecular beam epitaxy were examined as a function of the thickness of the Si interface layer and the intensity of the As or Al flux employed during Si deposition. We f ound that Schottky barriers as low as 0.3-0.4 eV (in the presence of a sufficiently high As flux) or as high as 1.0-1.1 eV (in the presence of a sufficiently high Al flux) can be established on n-type GaAs at S i coverages in the submonolayer to monolayer range. We therefore assoc iate the tunability of the barrier height with a Si-induced local inte rface dipole.