145-MW/cm2 Heteroepitaxial Diamond MOSFETs With NO2 p-Type Doping and an Al2O3 Passivation Layer

• Published in: IEEE electron device letters 2020-07, Vol.41 (7), p.1066-1069
• Main Authors: Saha, Niloy Chandra, Oishi, Toshiyuki, Kim, Seongwoo, Kawamata, Yuki, Koyama, Koji, Kasu, Makoto
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Al₂O; Breakdown; Current density; Current leakage; Diamond; diamond MOSFET; Diamonds; Doping; Field effect transistors; heteroepitaxial diamond; Leakage current; Logic gates; Maximum power density; Metal oxide semiconductors; MOSFET; MOSFETs; Nitrogen dioxide; NO₂ p-type doping; Passivation; Passivity; Semiconductor devices; Single crystals; Substrates
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2020.2997897

In this study, we investigated diamond metal oxide semiconductor field effect transistors (MOSFETs) with NO 2 p-type doping and Al 2 O 3 passivation layer fabricated on a high-quality heteroepitaxial single crystal (001) diamond substrate called Kenzan diamond ® . MOSFETs with a gate length of 1.4 \mu \text{m} and nearly zero source-gate spacing exhibited a high drain current density of −776 mA/mm with a negligible gate leakage current ( < 0.1~\mu \text{A} /mm). MOSFETs with a gate-to-drain length of 4.8 \mu \text{m} delivered a high off-state breakdown voltage (−618 V) at an average breakdown field of 1.2 MV/cm and a specific on-resistance of 2.63 \text{m}\Omega \cdot cm 2 . Baliga's Figure-Of-Merits was calculated as 145 MW/cm 2 and the anticipated maximum power density was 12 W/mm. The diamond MOSFET was improved with high crystal quality.