Electrical Properties of Boron-Doped Diamond MOSFETs With Ozone as Oxygen Precursor for Al2O3 Deposition

Boron-doped diamond (B-diamond) MOS capacitors and MOSFETs are fabricated and characterized. The Al2O3 gate insulator is deposited by an atomic layer deposition (ALD) technique with ozone as oxygen precursor. Leakage current density for the Al2O3 (ozone)/B-diamond MOS capacitor is
$2.7\times 10^{-{5}}$
A/cm2 at–9.0 V. Comparing to the capacitance–voltage (CV) curve of the Al2O3 (water)/B-diamond MOS capacitor, there is no residual capacitance and improved negative flat band voltage shift for the Al2O3 (ozone)/B-diamond MOS capacitor. The Al2O3 (ozone)/B-diamond MOSFET operates well with the ON/OFF ratio of around
$10^{8}$
, which is much higher than that of the previous Al2O3 (water)/B-diamond MOSFET. After annealing at 500 °C for as long as 10 h, the Al2O3 (ozone)/B-diamond MOSFET can still operate well with the ON/OFF ratio larger than
$10^{6}$
.