4 inch Gallium Oxide Field‐Effect Transistors Array with High‐k Ta₂O₅ as Gate Dielectric by Physical Vapor Deposition

Field‐effect transistors (FETs) with ultra‐wide bandgap semiconductor Ga 2 O 3 have been fabricated by physical vapor deposition with advantages of low cost, wafer scale, and rapid production. The insulator‐like pristine Ga 2 O 3 is converted to semiconductor by co‐sputtering Sn with post‐annealing, which demonstrates a 5.6 × 10 7 times higher on‐state current. Importantly, this Sn‐doped Ga 2 O 3 sample shows a high breakdown voltage near 500 V. Furthermore, a 4 inch array of Sn‐doped Ga 2 O 3 FETs with high‐k Ta 2 O 5 gate dielectric has been fabricated on a silicon substrate, successfully showing a large on‐current density of 1.3 mA mm −1 , a high I ON / I OFF of 2.5 × 10 6 , and a low threshold voltage of 3.9 V, which are extracted from the average 350 devices. This work paves a promising way for Ga 2 O 3 ‐based nanoelectronics to serve medium‐high voltage with low cost, rapid, and wafer‐scale production.