10-kV Lateral -Ga₂O₃ MESFETs With B Ion Implanted Planar Isolation

In the letter, high performance lateral beta-Ga2O3 metal-semiconductor field effect transistors (MESFETs) with ultra-high breakdown voltage (V-br) over 10 kV are demonstrated. Planar isolation is realized by B ion implantation to avoid the ragged mesa edge and damage induced by traditional dry etching. A T-shaped gate and source field plate (FP) were adopted to suppress the peak electric field in both Ga2O3 channel and SiNx passivation layer. The planar isolated MESFETs with source-drain length of 103 mu m that use an in-situ unintentionally doped (UID) Ga2O3 cap layer as a gate dielectric showed a maximum destructive breakdown voltage of greater than 10 kV, combined with the specific on-resistance (R-on, (sp)) of 2922 m Omega center dot cm(2), a power figure of merit (PFOM) more than 34.2 MW/cm(2) is obtained. The results suggest that the B ion implanted isolation and device structure used in this work improve the performance of lateral beta-Ga2O3 MESFETs.