Schottky barrier height reduction by oxide layer insertion in Al/n-GaN structure

The purpose of this work is to obtain the low specific contact resistivity on n-GaN. We investigated the Schottky barrier height between various metals and GaN and found that Fermi level pinning occurred at the interface between metals and GaN. We also attempted to reduce the specific contact resistivity using MIS structure in order to release Fermi level pinning. We selected GaO
x
and TiO
x
for the insulator materials and obtained the low specific contact resistivity of 7.1×10
⁻⁷
Ω·cm
²
with GaO
x
on n-GaN having Si doping concentration of 2×10
¹⁸
cm
⁻³
.