Title :
Low temperature conductivity in plasma deposited amorphous dielectric films
Author :
Tyczkowski, J. ; Kazimierski, P.
Author_Institution :
Centre of Molecular & Macromolecular Studies, Polish Acad. of Sci., Sienkiewicza, Poland
Abstract :
Investigations on electrical properties of amorphous dielectric films have revealed, in some cases, a measurable conductivity at low temperatures (down to 77 K). This effect was attributed to variable range hopping between states lying near the Fermi level and was described by Mott´s law. Subsequent studies, however, carried out over much broader temperature ranges, have shown that Mott´s law is not satisfied and the conductivity at a given electric field becomes completely temperature independent below a critical temperature. This phenomenon is studied based on measured DC conductivity at low temperatures and voltage-pulse-induced time-domain depolarization (VPITDD) experiments. Samples of films deposited by plasma decomposition of hexamethyldisilazane, hexamethyldisiloxane, and tetramethylsilane were investigated. Although the results obtained seem to confirm the existence of a second transport channel in some amorphous dielectric films, the nature of states responsible for this mechanism is not yet known
Keywords :
dielectric thin films; electrical conductivity of amorphous semiconductors and insulators; electronic conduction in insulating thin films; hopping conduction; plasma deposited coatings; 77 K; DC conductivity; Mott´s law; hexamethyldisilazane; hexamethyldisiloxane; low temperatures; plasma decomposition; plasma deposited amorphous dielectric films; second transport channel; tetramethylsilane; variable range hopping; voltage-pulse-induced time-domain depolarization; Amorphous materials; Conductivity measurement; Dielectric films; Dielectric measurements; Electric variables measurement; Low voltage; Plasma measurements; Plasma properties; Plasma temperature; Temperature distribution;
Conference_Titel :
Conduction and Breakdown in Solid Dielectrics, 1992., Proceedings of the 4th International Conference on
Conference_Location :
Sestri Levante
Print_ISBN :
0-7803-0129-3
DOI :
10.1109/ICSD.1992.224964