130 mA mm⁻¹ β-Ga₂O₃ metal semiconductor field effect transistor with low-temperature metalorganic vapor phase epitaxy-regrown ohmic contacts

Abstract

We report on the first demonstration of metalorganic vapor phase epitaxy-regrown (MOVPE) ohmic contacts in an all MOVPE-grown β-Ga2O3 metal semiconductor field effect transistor (MESFET). The low-temperature (600 °C) heavy (n+) Si-doped regrown layers exhibit extremely high conductivity with a sheet resistance of 73 Ω/□ and a record low metal/n+-Ga2O3 contact resistance of 80 mΩ·mm and specific contact resistivity of 8.3 × 10−7 Ω·cm2 were achieved. The fabricated MESFETs exhibit a maximum ON current of 130 mA mm−1 and a high ION/IOFF ratio of >1010. Thermal characterization was also performed to assess the device self-heating under the high current and power conditions.