Electrical and carrier transport properties of Au/Pr6O11/n-GaN MIS structure with a high-k rare-earth oxide interlayer at high temperature range

Abstract

The electrical and carrier transport properties of Au/Pr6O11/n-GaN metal/interlayer/semiconductor (MIS) structure with an electron beam deposited high-k rare-earth oxide as an interlayer have been investigated in the temperature range of 270–420 K. The electrical characteristics such as current–voltage (I–V), turn-on voltage and series resistance (RS) are analyzed at different temperatures. These analysis showed that the obtained barrier heights (Φb) increase while ideality factor (n) and RS decrease with increasing temperature. The characteristic temperature (T0) is determined from the RS against temperature plots, and the value (T0) is well matched with each other. The calculated thermal coefficient (Kj) value is – 2.1 mV/K at ≥ 270 K. The obtained effective barrier height (1.22 eV) is consistent with the theoretical value. The temperature-dependent ideality factor values are in good agreement with characteristic energy of 31 meV. The estimated interface state density (NSS) increases with decreasing temperature that could be associated with the molecular restructuring and reordering of the Pr6O11/n-GaN interface. The reverse bias results showed that the current conduction is dominated by Poole-Frenkel emission in the temperature range of 270–330 K while the Schottky emission is dominated in the temperature range of 360–420 K.