Academic Discourse
Year : 2022, Volume : 11, Issue : 2
First page : ( 51) Last page : ( 57)
Print ISSN : 2278-3296. Online ISSN : 2349-4441.

Electrical breakdown voltage and conduction studies of tantalum oxide thin films

Dr. Katyal Parveen

Associate Professor Department of Chemistry, S.D. (P.G.) College, Panipat, (Haryana)

Online published on 17 April, 2023.

Abstract

Electrical breakdown voltage and conduction studies of tantalum oxide thin films in various aqueous electrolytes at various concentrations and compositions at different temperatures have been obtained. Electrical breakdown voltage (VB) is found to be independent of current density used for film formation, field strength, topography of the specimen and pH of the electrolyte solution. It has been found to be dependent on the electrolyte concentration, resistivity, nature of the aqueous electrolyte and temperature employed. The effect of electrolyte concentration, composition and resistivity on breakdown characteristics has been explained in terms of Ikonopisov's electron injecting avalanche breakdown model. It has been found that anions from the electrolyte get incorporated into the oxide film which increases with the electrolyte concentration. These incorporated anions result in the formation of traps and the traps are in equilibrium with the electrolyte. The electrons are thermally excited continuously from the traps into the conduction band and electronic equilibrium is maintained by the continuous injection of electrons from the electrolyte. The high field strength accelerates these electrons to an energy which is sufficient to free other electrons by impact ionization so that avalanche multiplication occurs and causes electrical breakdown when a certain critical current is reached. The appearance of sparking has been found to be superior method of the various methods of identifying electrical breakdown voltage. The exact mechanism of electrical breakdown during anodization has been developed.

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