[TuP3C] Power Devices

[TuP3C-15] Electrical Characteristics of β-Ga₂O₃ Recess-Gate MOSFETs With Different UID Layer Thicknesses

〇Wei-Jhe Chen¹, Nien-Yao Tsou¹, Ray-Hua Horng¹ (1. National Yang Ming Chiao Tung University (Taiwan))

Heteroepitaxial β-Ga₂O₃ films were grown by metalorganic chemical vapor deposition on c-plane and 10° A-off-cut sapphire substrates. Gate-recessed β-Ga₂O₃ MOSFETs fabricated on off-cut substrates exhibit superior electrical performance. It was found that increasing the unintentionally doped (UID) layer thickness can enhance the drain current and reduce the specific on-resistance. In contrast, for devices on exact c-plane substrates, thicker UID layers lead to increased surface roughness and degraded electrical characteristics. Notably, β-Ga₂O₃ films grown on 10° A-off-cut sapphire maintain low surface roughness even with increased UID thickness, enabling improved channel quality and enhanced device performance. These results indicate that combining off-cut sapphire substrates with optimized UID thickness is an effective strategy for improving β-Ga₂O₃ recess-gate MOSFET performance.