Stability of H-Terminated Diamond MOSFETs With V₂O₅/Al₂O₃ as Gate Insulator

The effectiveness and long-term stability of the surface transfer doping of H-terminated diamond induced by a very thin V ₂ O ₅ /Al ₂ O ₃ double layer were deeply investigated. The experimental results demonstrate that the deposition of a 5 nm Al ₂ O ₃ layer does not alter the transfer doping properties of the V ₂ O ₅ /H-terminated diamond interface and remarkably improves the stability of the Hall parameters over time. The H-diamond MOSFETs were fabricated by using V ₂ O ₅ /Al ₂ O ₃ as gate insulator and characterized in terms of DC characteristics. The devices showed a saturation drain current density of about 220 mA/mm. The repeated measurements of the DC output characteristics of the MOSFETs were performed and monitored over a period of one month. The variations within ±0.9 % of the drain current and ±0.2 % of the ON-resistance were recorded, demonstrating very high stability of such devices over time.