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

Abstract

Field‐effect transistors (FETs) with ultra‐wide bandgap semiconductor Ga2O3 have been fabricated by physical vapor deposition with advantages of low cost, wafer scale, and rapid production. The insulator‐like pristine Ga2O3 is converted to semiconductor by co‐sputtering Sn with post‐annealing, which demonstrates a 5.6 × 107 times higher on‐state current. Importantly, this Sn‐doped Ga2O3 sample shows a high breakdown voltage near 500 V. Furthermore, a 4 inch array of Sn‐doped Ga2O3 FETs with high‐k Ta2O5 gate dielectric has been fabricated on a silicon substrate, successfully showing a large on‐current density of 1.3 mA mm−1, a high ION/IOFF of 2.5 × 106, and a low threshold voltage of 3.9 V, which are extracted from the average 350 devices. This work paves a promising way for Ga2O3‐based nanoelectronics to serve medium‐high voltage with low cost, rapid, and wafer‐scale production.