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

Abstract

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 Iinv 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 qϕb 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 qϕb behavior. The series resistance Rs 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.

A new approach to studying the electrical behavior and the inhomogeneities of the Schottky barrier height

“…[33,34]. Then, the wafers were nitrided using a glow discharge nitrogen plasma source, of 5 W for 30 min, and annealed at 620 °C for 1 h, in an UHV chamber [3,[35][36][37]. In-situ, Au dots were deposited by evaporation on the top side with a 0.6 mm diameter and 100 nm of thickness, for the two samples, using a Knudsen cell.…”

“…Schottky barrier diodes (SBDs) have been widely studied in recent years due to their potential applications [1][2][3][4][5][6][7][8][9]. Several attempts have been performed to comprehend the electrical behavior and transport mechanisms through SBDs, in order to explain the observed phenomena.…”