High quality Al2O3/(100) oxygen-terminated diamond interface for MOSFETs fabrication

In this letter, we report on the improvement of gate controlled Al2O3/(100) boron doped (B-doped) oxygen-terminated diamond (O-diamond) Metal Oxide Semiconductor Capacitors using 40 nm thick Al2O3 deposited by Atomic Layer Deposition at 380 degrees C and then annealed at 500 degrees C in vacuum conditions. The high quality of Al2O3 and an Al2O3/diamond interface is verified thanks to electrical measurements and Transmission Electron Microscopy (TEM) measurements. A density of interface states lower than 10(12) eV(-1) cm(-2) is measured from the flat-band regime to the depletion regime. The shift of the flat-band voltage and the leakage current through the oxide are significantly reduced in good agreement with the mono-crystalline character of the Al2O3 layer revealed by TEM. Published by AIP Publishing.