Performance study of non-recess structure for β-Ga2O3 MOSFETs applications

In this work, high-quality β-Ga 2 O 3 epitaxial layers were grown on c-plane sapphire substrates via metalorganic chemical vapor deposition. The device structure sequentially comprised a heavily doped Ga 2 O 3 layer (10 nm), a lightly doped Ga 2 O 3 layer (10 nm), an (Al 0.21 Ga 0.79 ) 2 O 3 layer (10 nm), and an unintentionally doped (UID) Ga 2 O 3 epilayer. To induce the formation of a two-dimensional electron gas, the (Al 0.21 Ga 0.79 ) 2 O 3 layer was inserted between the lightly doped Ga 2 O 3 and the UID Ga 2 O 3 layers. A novel non-recess etching process was employed to avoid plasma-induced damage, thereby improving the performance of β-Ga 2 O 3 metal-oxide-semiconductor field-effect transistors. This approach enhanced the on-state drain current (Iₒₙ), the Iₒₙ/Iₒ ff ratio of the drain current, and low oxide trap density, while simultaneously simplifying the fabrication process. Electrical characterizations confirmed the superior device performance enabled by this novel structure.