Thermally stable rhenium Schottky contacts to n-GaN

The barrier heights of Re Schottky contacts to n-GaN were investigated by c urrent-voltage (I-V) and capacitance-voltage (C-V) measurements. Both techn iques indicate that the barrier height increases upon annealing at 500 degr ees C for 10 min. After this anneal, a barrier height of 0.82 eV and ideali ty factor of 1.1 are obtained by I-V measurements performed at 150 degrees C, The C-V measurements performed at room temperature reveal a barrier heig ht of 1.06 eV, These barrier heights are stable upon further short term ann ealing at temperatures as high as 700 degrees C, The Re Schottky contacts w ere also stable upon prolonged annealing for 24 h at 300 degrees C. The Re/ n-GaN Schottky diode was chosen for study because of its anticipated thermo dynamic stability against metallurgical reactions. (C) 1998 American Instit ute of Physics. [S0003-6951(98)02335-3].