Abstract :
Rectifying contact formation on n-type bulk single crystal ZnO using novelW2B orW2B5 metallization schemes was studied
using current–voltage, scanning electron microscopy and Auger electron spectroscopy (AES) measurements. When a single Au
overlayer was used to reduce the metal sheet resistance, the contacts were ohmic for all annealing conditions due to outdiffusion
of Zn through the metal. By sharp contrast, when a bilayer of Pt/Au was used on top of the boride layers, rectifying contacts with
barrier heights of 0.4 eV for W2B were obtained. The highest barrier height of 0.66 eV was achieved for W2B5 annealed at
600 8C, although at this condition the contact showed a reacted appearance and AES showed almost complete intermixing of the
metallization
