Characterization of β-Ga2O3 interface and conduction band offset with GaN using a Sol-gel process of deposition

Significant efforts have been reported on oxide dielectrics on GaN and their role on device performance. It has been noted by several researchers [1, 2] that a few monolayers of native Ga
2
O
3
decorate the GaN surface due to the spontaneous termination of the Ga-atoms with Oxygen. In an attempt to characterize the quality of Ga
2
O
3
and GaN interfaces and evaluate its band offset on GaN, we have successfully deposited Ga
2
O
3
on GaN using a sol-gel process developed by Kaya et al. [3, 4]. In this work, we report successful deposition of the sol-gel process enabled thin-film of Ga
2
O
3
on n-type GaN with the assistance of photochemical reaction involving the exposure to the UV light. Interface-state density and conduction band offset between Ga
2
O
3
and GaN were characterized on Au/Al/Ga
2
O
3
/GaN MOS capacitors.