FORMATION OF OXIDE-FREE NEARLY IDEAL PT/GAAS SCHOTTKY BARRIERS BY NOVEL IN-SITU PHOTOPULSE-ASSISTED ELECTROCHEMICAL PROCESS

An oxide-free Pt/GaAs Schottky barrier was fabricated by a novel in situ photopulse-assisted electrochemical process. Nearly ideal thermionic emission characteristics of a high barrier height phi(Bn) of 1.07 eV and an ideality factor of n=1.05, were observed over a range of 7 orders of magnitude of electric current. The results of atomic force microscopy (AFM), X-ray photoemission spectroscopy (XPS) and deep level transient spectroscopy (DLTS) measurements indicated that the novel electrochemical process produces a smooth and oxide-free interface and prevents formation of process-induced damage. It produces firm Fermi level pinning which was previously possible only by ultrahigh-vacuum (UHV) processes.