Rhodium Germanide Schottky Barrier Contacts

Rhodium Schottky barrier contacts on germanium substrates are investigated in terms of electrical, physical, and chemical properties. The Rh, deposited by electron beam evaporation on a n-type (100)-Ge substrate, has been annealed in N2H2 at different temperatures ranging from 450 degrees C up to 800 degrees C. Rh/Ge Schottky diodes were fabricated to extract the Schottky barrier height, the ideality factor as well as the forward to backward current ratio. By using various analyzing techniques such as Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), and High-resolution Transmission Electron Microscopy (HR-TEM), the formation of polycrystalline Rh-germanide RhxGey phases has been proven. At 500 degrees C germanidation temperature an effective SBH of 0.59 eV is extracted showing a high current ratio of 5 x 10(3) and a remarkable low ideality factor of 1.07. (C) 2015 The Electrochemical Society. All rights reserved.