Conduction Mechanisms in Au/0.8 nm-GaN/n-GaAs Schottky Contacts in a Wide Temperature Range

Au/0.8 nm-GaN/n-GaAs Schottky diodes were manufactured and electrically characterized over a wide temperature range. As a result, the reverse current I increments from 1 × 10^-7 A at 80 K to about 1 × 10^-5 A at 420 K. The ideality factor n shows low values, decreasing from 2 at 80 K to 1.01 at 420 K. The barrier height qϕ grows abnormally from 0.46 eV at 80 K to 0.83 eV at 420 K. The tunnel mechanism TFE effect is the responsible for the qϕ behavior. The series resistance R is very low, decreasing from 13.80 Ω at 80 K to 4.26 Ω at 420 K. These good results are due to the good quality of the interface treated by the nitridation process. However, the disadvantage of the nitridation treatment is the fact that the GaN thin layer causes an inhomogeneous barrier height.