Structural and electrical properties of Mo/n‐GaN Schottky diodes

The electrical and structural properties of molybdenum (Mo) Schottky contact to n‐type GaN (4.07 × 1018 cm–3) have been investigated before and after annealing at 600 °C. Measurements show that the Schottky barrier height of the as‐deposited sample was 0.81 eV (I–V) and 1.02 eV (C–V), respectively. It is shown that when the sample is annealed at 400 °C the Schottky barrier height slightly decreases to 0.74 eV (I–V) and 0.92 eV (C–V), respectively. However, the barrier height degraded to 0.56 and 0.73 eV when the sample was annealed at 600 °C for 1 min in nitrogen ambient. Based on the Auger electron microscopy and X‐ray diffraction results, the formation of nitride phases at the Mo/n‐GaN interface could be the reason for degradation of Schottky barrier height upon annealing at 600 °C. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)