Improved hot-carrier reliability of SOI transistors by deuterium passivation of defects at oxide/silicon interfaces

The effect of deuterium on hot-carrier reliability of fully processed 0.18 μm silicon-on-insulator (SOI) devices is investigated. The improvement of device lifetime by a factor of 30 is achieved by passivating the interface defects with deuterium instead of hydrogen. The hydrogen/deuterium isotope effect (γ), defined as the ratio of generation interface traps of a hydrogenated device to that of a deuterated one, shows strong dependence on the gate stress voltages (Vgs). Increasing Vgs results in the decrease of γ. These results suggest that the breaking of Si-H(D) bonds by channel electrons through the vibrational heating mechanism may play an important role in the degradation of deep submicron SOI devices.