Current deep level transient spectroscopy analysis of AlInN/GaN high electron mobility transistors: Mechanism of gate leakage

Abstract

In order to assess possible mechanisms of gate reverse-bias leakage current in AlInN/GaN high electron mobility transistors (HEMTs) grown by metalorganic chemical-vapor deposition on SiC substrates, temperature-dependent current-voltage measurements combined with Fourier transform current deep level transient spectroscopy (FT-CDLTS) are performed in the temperature range of 200–400 K. In this range of temperature reverse-bias leakage current flow is found to be dominated by Poole–Frenkel emission. Based on CDLTS measurements, a model of leakage current transport via a trap state located at the AlInN/metal interface with an activation energy of 0.37 eV is suggested. The trap nature is shown to be an extended trap, most probably associated with dislocations in the AlInN barrier layer.

Fabrication and characterization of InAlN/GaN-based double-channel high electron mobility transistors for electronic applications

“…This very low leakage is linked to high-insulating GaN buffer and high quality Schottky diode as well as absence of defects into the upper InAlN barrier layer resulting from high growth quality by PMOCVD, as revealed that the gate reverse-bias leakage current is associated with dislocations in the InAlN barrier layer. 23 As shown in Fig. 4, when the device is pinched off below À7 gate bias, the drain leakage current is dominated by reverse-biased gate current, and no leakage current through the buffer is observed, which is in agreement with the device process result and a proof of highresistive GaN buffer.…”

Characterization and analysis of electrical trap related effects on the reliability of AlInN/GaN HEMTs

“…So, η and Φ b are equal to 3.7 and 0.53 eV, respectively. The origin of the high ideality factor may be related to a generationrecombination, or Poole-Frenkel or tunnelling mechanisms [8]. No change in η and Φ b has been observed after an ageing time of 216 h. Similarly, the pinch-off voltage (V P ) stayed equal to − 4 V after the ageing test.…”

High conductive gate leakage current channels induced by In segregation around screw- and mixed-type threading dislocations in lattice-matched InxAl1−xN/GaN heterostructures

“…However, there is generally very high gate leakage current density of Schottky contacts under reverse bias, which is a severe problem hindering the applications of In x Al 1−x N / GaN HEMTs. 1,5,6 Arslan et al, 5 Chikhaoui et al, 6 and Donoval et al 7 analyzed the mechanisms of gate leakage current of Schottky contacts on In x Al 1−x N / GaN heterostructures. They suggested that the reverse-bias gate leakage current was dominated by Frenkel-Poole emission associated with dislocations in the In x Al 1−x N barrier.…”