Etching mechanism of β -Ga2O3 in BCl3/Ar inductively coupled plasma reactive ion etching

We report on the study of the etching mechanism of beta gallium oxide (β-Ga2O3) through the inductively coupled plasma reactive-ion etching (ICP RIE) mechanism using chloride (BCl3/Ar) based plasma. We primarily focus on the mechanism of etching of β-Ga2O3 using BCl3/Ar plasma. The samples were etched for different ICP and RF powers. The obtained results help understand the different mechanisms that are responsible for etching gallium oxide. We found different limiting mechanisms under various RF and ICP powers. We also report on the mechanism of an intermediate heterogeneous complex formation that helps in the etching of gallium oxide. Furthermore, a 4 μm deep trench was etched to show the efficacy of the recipe. The study presented in this report will help better understand the etching mechanism in β-Ga2O3, which is still at a very nascent stage, and help in fabricating power devices with high aspect ratio trenches.