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Pellets of ceramic, Na 1-x K x NbO 3 (x = 0, 0⋅ ⋅2 and 0⋅ ⋅5), were prepared by conventional solid-state reaction method. Prepared samples were characterized using XRD and SEM. The frequency and temperature variation of dielectric constant, loss tangent and dielectric conductivity of prepared samples were measured in the frequency range from 10 KHz-1 MHz, and in the temperature range from 50-250°C for x = 0⋅ ⋅2 and 0⋅ ⋅5, and between 50 and 480°C for x = 0 compositions. It was observed that the dielectric constant and loss tangent decrease, and conductivity increases with increasing frequency. Near the transition temperature the material shows anomalous behaviour for the observed properties, and the peaks of dielectric constant and loss tangent were observed shifting towards lower temperature with increasing frequency.

Scanning magnetron-sputtered titanium nitride (TiN) films were deposited onto silicon substrates under varying nitrogen and argon pressures. Golden TiN films with (220) orientation were deposited at different substrate bias voltages (0to−120V). Auger electron spectroscopy measurements show N∕Ti ratio between 1.18 and 1.07, and oxygen content between 11% and 5% in the as-deposited TiN film samples. Dependence of the stress and grain size on substrate bias voltage and dependence of resistivity on bias voltage and annealing temperature have been studied for the deposited TiN films. Resistivity was found minimum for the TiN samples deposited at −40V bias, which decreases from 320to132μΩcm on annealing, up to 750°C. Copper was sputter deposited on the as-grown TiN films deposited at −40V bias. The Cu∕TiN∕Si samples were annealed at different temperatures. Resistivity, x-ray diffraction, scanning electron microscopy, and energy dispersive x-ray analysis results of the Cu∕TiN∕Si structure are consistent with each other, and show that scanning magnetron sputtering deposited TiN film is a good diffusion barrier for copper metallization of the silicon devices, up to 750°C.

By radio-frequency magnetron sputtering of bulk NaNbO3 pellet targets, films of NaNbO3 have been deposited on silicon substrates at different temperatures. Room-temperature deposited films have been annealed at different temperatures. Film samples have been characterized using an x-ray diffraction method. The room-temperature deposited films show a crystalline structure with different orientations, and films deposited at 225 and 270 °C show a crystalline structure with a single-face orientation. Films deposited at 300 °C and higher temperatures show an amorphous nature. Annealing up to 500 °C changes the orientation of the room-temperature deposited films, and annealing at and beyond 600 °C results in amorphous films. Capacitance–voltage measurements have been carried out in a metal–insulator–semiconductor configuration by sandwiching a NaNbO3 film between aluminum and silicon. Structural and capacitance–voltage characteristics of the films have been found to be sensitive to sodium and oxygen stoichiometry. Hysteresis in the capacitance–voltage measurements indicates hole injection in the annealed films and electron injection in the films deposited at different temperatures. From the observed characteristics, the capacitance of the accumulation region, capacitance of inversion region, flat-band capacitance, flat-band voltage, amount of hysteresis, density of states, density of interface states, dielectric constant, maximum capacitance of depletion layer, and maximum depletion width have been calculated for the prepared samples. In the crystalline films, with increasing deposition or annealing temperature, the dielectric constant tends to that of the bulk. The charge storage capacity, charge storage density, density of states, and density of interface states for NaNbO3-assisted metal–insulator–semiconductor structure have been found to be quite larger as compared to reported values for other materials, which suggests the superior potential of NaNbO3 films for memory applications.

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