US Patent 9484208 Preparation method of a germanium-based schottky junction

The present invention discloses a preparation method of a germanium-based Schottky junction, comprising, cleaning a surface of N-type germanium-based substrate, then depositing a layer of CeO2 on the surface, and further depositing a layer of metal. The stability Ce—O—Ge bonds can be formed at the interface after rare earth oxides CeO2 are in contact with the germanium substrate, and this is beneficial to reduce the interface state density, improve the quality of the interface, and reduce the MIGS and suppress Fermi-level pinning. Meanwhile, the tunneling resistance introduced by CeO2 between the metal and the germanium substrate is smaller relative to the case of Si3N4, Al2O3, Ge3N4 or the like. In view of the excellent surface characteristics and small conduction band offset relative to the germanium substrate, interposing of the CeO2 dielectric layer is applicable to the preparation the germanium-based Schottky junction having a low resistivity.