Multi-kV class \(\beta\)-Ga\(_2\)O\(_3\) MESFETs with a Lateral Figure of Merit up to 355 MW/cm\(^2\)

• Published in: arXiv.org 2021-07
• Main Authors: Bhattacharyya, Arkka, Praneeth Ranga, Roy, Saurav, Peterson, Carl, Fikadu Alema, Seryogin, George, Osinsky, Andrei, Krishnamoorthy, Sriram
• Format: Article
• Language: English
• Subjects: Contact resistance; Depletion; Epitaxial growth; Field effect transistors; Figure of merit; Low temperature; Metalorganic chemical vapor deposition; Vapor phase epitaxy; Vapor phases
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2106.06661

We demonstrate over 3 kV gate-pad-connected field plated (GPFP) \(\beta\)-Ga\(_2\)O\(_3\) lateral MESFETs with high lateral figure of merit (LFOM) using metalorganic vapor phase epitaxy (MOVPE) grown channel layers and regrown ohmic contact layers. Using an improved low-temperature MOVPE selective area epitaxy process, we show that a total contact resistance to the channel as low as 1.4 \(\Omega\).mm can be achieved.The GPFP design adopted here using PECVD (plasma-enhanced chemical vapor deposition) deposited SiN\(_x\) dielectric and SiN\(_x\)/SiO\(_2\) wrap-around passivation exhibits up to ~14% improved R\(_{ON}\), up to ~70% improved breakdown voltage (V\(_{BR}\) = V\(_{DS}\) - V\(_{GS}\)) resulting in up to \(\sim\)3\(\times\) higher LFOM compared to non-FP \(\beta\)-Ga\(_2\)O\(_3\) lateral MESFETs. The V\(_{BR}\) (~2.5 kV) and LFOM (355 MW/cm\(^2\)) measured simultaneously in our GPFP \(\beta\)-Ga\(_2\)O\(_3\) lateral MESFET (with L\(_{GD}\) = 10 \(\mu\)m) is the highest value achieved in any depletion-mode \(\beta\)-Ga\(_2\)O\(_3\) lateral device.