Threshold switching induced by joule heating

The work contained in this thesis is an experimental and theoretical one on thin film threshold switching devices. The used active, semiconductor layers were amorphous boron and polycrystalline and amorphous vanadium dioxide. The static current-voltage characteristics were particularly investigated, the key parameter being the ambient temperature. The quantitative study of the resistive region before the threshold and also of the parameters of the threshold permit a better knowledge of the origins of the phenomena. The comparison of these results and of these published on amorphous chalcogenides permit to give some general conclusions about switching phenomena. Concerning the conducting state obtained after the threshold was reached, it was interpreted in terms of filamentary conduction. Direct observations allowed me to plot electrical parameters versus filament width and to drive conclusions about the filamentary temperature profile in the semi-conductor. I have made a list of applications of switching devices: solid state switch, temperature detector, integrated bistable and oscillating circuits. (author)