The generation of interface defects and positive charge during the injection of electrons in p-Si/SiO2/ZrO2/TiN structures is investigated. The kinetics of generation of both type of defects are found to be very similar. A model is proposed to explain the interface defect generation, based on the depassivation of trivalent silicon dangling bonds (Si3≡SiH→Si3≡Si⋅) at the (100)Si/SiO2 interface by the injected electrons. A Gaussian spread for the activation energy Ed related to the dissociation of the Si–H bond is included in this model. Comparison with experimental results reveals that the mean value of the activation energy Edi decreases linearly with the electric field Eox across the SiO2 layer. This behavior is attributed to the alignment of the Si–H dipole moment with respect to Eox, which favors dissociation of the Si–H bond. The hint of a correlation between the interface defect and positive charge generation suggests that the positively charged centers might be hydrogen-induced overcoordinated oxygen centers.

The impact of hydrogen on negative bias temperature instability in atomic layer deposited HfO2-based hole channel field-effect transistors is investigated. After forming gas anneal of the devices at high temperature (580°C), the saturated threshold voltage shift of the transistor is about 100mV at 125°C. The threshold voltage instability is reduced to about a factor of 2 for devices annealed in forming gas at 520°C. A detailed analysis of the experimental results suggests that the defects responsible for negative bias temperature instabilities are hydrogen-induced overcoordinated oxygen centers, due to the transport and trapping of protons in the gate dielectric stack.

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International audienceThe interactions of thermal and low energy (<1 MeV) neutrons with natural boron-doped silicon has been investigated using Geant4 numerical simulations. The consequences of these interactions on the soft-error rate of 40 nm SRAM at ground level have been carefully analyzed and quantified from thermal neutron accelerated tests at LLB facility, real-time altitude measurements on the ASTEP platform and numerical simulation using a new version of the TIARA Monte-Carlo code (TIARA-G4) capable of taking into account a more accurate description of the SRAM geometry and the true isotopic composition of circuit materials from silicon to back-end-of-line levels