Deep level study of chlorine-based dry etched β - Ga2O3

Chlorine-based gases are used for the reactive ion etching (RIE) of beta-Ga2O3. However, the effects of Cl-plasma on the electronic properties of beta-Ga2O3 are not known. In order to shed light on this topic, we carried out an experimental and theoretical study on beta-Ga2O3 epilayers treated with Cl-2/Ar or BCl3/Ar plasma. We found four traps in the 0.2-0.8 eV energy range below the conduction band edge (EC). Two of these, located at EC-0.24 eV and EC-0.28 eV, arise only when the epilayers are treated with BCl3/Ar. While the involvement of Cl in their microscopic structure is not discarded, the possibility that these two levels might have an intrinsic nature seems more plausible. Our findings might explain the reported effects on the Schottky barrier diodes of beta-Ga2O3 when RIE is employed during processing. Published under an exclusive license by AIP Publishing.

Automated summary

This study investigates the effects of chlorine-based gases on the electronic properties of beta-Ga2O3. The experimental and theoretical research reveals the formation of four traps in the energy range below the conduction band edge, with two traps appearing only after treatment with BCl3/Ar plasma. The findings provide insight into the potential impact of Cl-plasma treatment on the electronic properties of beta-Ga2O3.