[11a-PB1-1~31] 13.7 Compound and power devices, process technology and characterization

[11a-PB1-17] Investigation of High-Selectivity MgO Etching Mask for GaN Deep-Trench Fabrication

Hiroshi Ohta¹, Tomoaki Nishimura¹, Tomoyoshi Mishima¹, Hirotaka Oosato², Masaaki Onomura², Daiju Tsuya², 〇FUMIMASA HORIKIRI¹ (1.Hosei Univ., 2.NIMS)

Keywords:

GaN,Dry etching,Etching Mask

There is a growing demand for the fabrication of high-aspect-ratio deep GaN trenches for applications such as trench MOSFETs and through-substrate vias in GaN-on-GaN HEMTs. To fabricate deep trench structures, a mask material with high selectivity against GaN is essential. Since MgO is used as a component in Cl₂-based dry etching equipment, it is expected to exhibit high selectivity to GaN in Cl₂-based etching processes. In this study, we evaluated the suitability of MgO as a mask material for GaN deep trench fabrication.