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The effect of increasing the tunnel current in a metal–calcium fluoride–silicon structure with addition of a silicon dioxide layer between fluoride and metal (which seems paradoxical at first glance) has been considered. This effect of nonmonotonic change in the tunnel conductivity with an increase in the insulator thickness may occur at a relatively high bias at the structure and is related to the tunnel-barrier deformation, at which electrons are tunneling through its part formed by the oxide. At low biases, the occurrence/ thickening of an additional layer leads to a natural decrease in the current. Similar behavior is possible in principle for some other combinations of materials.

The j–V characteristics of the Al/thermal or electrochemical SiO2(2–4 nm)/heavily doped p+-Si nanostructures operating as a resonant-tunneling diode were measured and theoretically analyzed. The characteristics have specific features in the form of current steps and peaks, which are caused by electron transport between the silicon valence band and metal through discrete levels of the quantum well formed by the p+-Si conduction band and SiO2/p+-Si interface. Resonant tunneling through the surface state levels and the appearance of a charge near this interface under certain conditions are discussed.

A technique for diagnostics of the injection properties of thin dielectric layers based on analysis of the data on silicon electroluminescence in a metal-insulator-semiconductor structure is proposed. The possibility of applying this technique to control the electron injection energy (in particular, when the barrier parameters are poorly known) is demonstrated by the example of samples with CaF2 and HfO2/SiO2. The results obtained are important for application of the insulators under study in microelectronic devices.

Thin (2–7 monolayer thick) layers of calcium fluoride (CaF2) of device quality have been obtained using molecular beam epitaxy on Si(111) substrates. The current-voltage characteristics of metal-insulator-semiconductor (MIS) structures with these films well correspond to theoretical results obtained with correctly taking into account the conserved transverse wave vector component of tunneling carriers. According to calculations, the tunneling currents in CaF2 based MIS structures are smaller than those in the standard structures with oxides used in field-effect transistors.

The characteristics of a planar 8 × 8 array of a 3-mm waveband receiver antenna elements loaded with low-barrier planar Mott diodes have been studied. Experimental data on the radiation-directivity patterns (RP) and sensitivity of antenna elements in the two-dimensional array are presented. The average RP width for central elements amounts to ∼35° in the E plane and ∼50° in the H plane. In the operating frequency range (90–100 GHz) of the matrix receiver, the average voltage responsivity is on the order of 9000 V/W at a noise equivalent power of about 5 × 10−12 W/Hz1/2.

An experimental investigation is made of the influence of strong self-interaction of the reference waves on phase conjugation in four-wave mixing of cw radiation in a medium with a thermal nonlinearity. It is shown that the thermal lens formed by the Gaussian reference beams reduces the nonlinear reflection coefficient appreciably (several-fold) and causes a deterioration in the phase conjugation quality.