4.4 kV \(\beta\)-Ga\(_2\)O\(_3\) Power MESFETs with Lateral Figure of Merit exceeding 100 MW/cm\(^2\)

• Published in: arXiv.org 2022-01
• Main Authors: Bhattacharyya, Arkka, Sharma, Shivam, Fikadu Alema, Praneeth Ranga, Roy, Saurav, Peterson, Carl, Seryogin, George, Osinsky, Andrei, Singisetti, Uttam, Krishnamoorthy, Sriram
• Format: Article
• Language: English
• Subjects: Breakdown; Damage prevention; Depletion; Etching; Field effect transistors; Figure of merit; Leakage; Semiconductor devices; Transistors
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2201.10028

Field-plated (FP) depletion-mode MOVPE-grown \(\beta\)-Ga\(_2\)O\(_3\) lateral MESFETs are realized with superior reverse breakdown voltages and ON currents. A sandwiched SiN\(_x\) dielectric field plate design was utilized that prevents etching-related damage in the active region and a deep mesa-etching was used to reduce reverse leakage. The device with L\(_{GD}\) = 34.5 \(\mu\)m exhibits an ON current (I\(_{DMAX}\)) of 56 mA/mm, a high I\(_{ON}\)/I\(_{OFF}\) ratio \(>\) 10\(^8\) and a very low reverse leakage until catastrophic breakdown at \(\sim\) 4.4kV. The highest measurable V\(_{BR}\) recorded was 4.57 kV (L\(_{GD}\) = 44.5 \(\mu\)m). An LFOM of 132 MW/cm\(^2\) was calculated for a V\(_{BR}\) of \(\sim\) 4.4 kV. The reported results are the first \(>\) 4kV-class Ga\(_2\)O\(_3\) transistors to surpass the theoretical FOM of Silicon. These are also the highest I\(_{DMAX}\) and lowest R\(_{ON}\) values achieved simultaneously for any \(\beta\)-Ga\(_2\)O\(_3\) device with V\(_{BR}\) \(>\) 4kV to date. This work highlights that high breakdown voltages (V\(_{BR}\)), high lateral figure of merit (LFOM) and high ON currents can be achieved simultaneously in \(\beta\)-Ga\(_2\)O\(_3\) lateral transistors.