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 × 10 18 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)