The crystal structures and electrical characteristics of Ti–Si–N metal–oxide–semiconductor (MOS) gate electrodes in the mictamict state, which is a comprehensive term referring to amorphous structures both with and without nanocrystals, were investigated. By increasing the N2 concentration of the sputtering ambient, the nitrogen (N) content of the Ti–Si–N films increased and consequently the Ti–Si–N films did not crystallize. At a N2 concentration of more than 3.0%, the N content of the films was almost constant at about 53%, which indicates that all Ti and Si atoms deposited in the form of TiN and Si3N4, respectively. In such Ti–Si–N films with a saturated N content, only 2–3-nm-grain-size nanocrystallites formed, which were embedded in amorphous layers even after post-deposition annealing (PDA) above 900 °C. At the same time, with increasing N2 concentration of the sputtering ambient, the change in the film resistivity after the PDA became smaller and the capacitance equivalent thickness (CET) fluctuation gradually ceased to occur. The work function of the mictamict Ti–Si–N gate electrodes, which were deposited in 5.0% N2 ambient and annealed at 500 °C, was determined to be 4.6 eV.

Degeneracy of energy levels of excited hydrogen atoms is not fully lifted by external perpendicular electric and magnetic fields in the first order of perturbation theory. Within the submanifold of residual degeneracy the levels splitting is governed by the second-order effects. The related classical electron trajectories exhibit instabilities characterized by the Lyapunov exponent. The present study establishes quantum mechanical implications of these instabilities. In particular, we derive from a quantum framework a simple analytical approximation for the Lyapunov exponent. The classical instabilities are linked to the presence of a diabatic quasistationary state in the quantum mechanical problem. Its meaning is elucidated by considering a related non-stationary quantum system with time-dependent field parameter. Some of the state-to-state transition probabilities are approximately expressed via Lyapunov exponents. Exact formulae for these probabilities are derived in the framework of multistate generalization of the Landau-Zener model. Nonadiabatic transitions are interpreted in terms of analytical properties of adiabatic potential curves.

The dependences of crystalline structures and resistivity of Hf-Si-N films on nitrogen content were investigated in this study. The nitrogen (N) content of Hf-Si-N films increases with increasing N 2 concentration in a N 2 /Ar mixture ambient used in sputtering, and saturates to about 59% at N 2 concentrations of 4.8% and above. This indicates that all Hf and Si atoms form HfN and Si 3 N 4 in the films, respectively. From X-ray diffraction (XRD) profiles, nanocrystallites exist even in as-deposited films with saturated N content. However, they hardly grow after post deposition annealing (PDA) at 900 C. The resistivity values are almost constant at N 2 concentrations of 4.8% and below. On the other hand, they significantly increase with increasing N 2 concentration above 4.8% and consequently become unmeasurable at N 2 concentrations of 13.0% and above. The XRD profiles indicate that nanocrystallites segregating in those films are related to Hf 3 N 4 .

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