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 V2O5/Al2O3 double layer were deeply investigated. The experimental results demonstrate that the deposition of a 5 nm Al2O3 layer does not alter the transfer doping properties of the V2O5/H-terminated diamond interface and remarkably improves the stability of the Hall parameters over time. The H-diamond MOSFETs were fabricated by using V2O5/Al2O3 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.