Electron and Ion Transport in Tantalum Capacitors under Steady-State Bias Conditions

conference paper

English

Degradation of leakage current (DCL) under steady-state bias conditions was investigated at temperature 400 K and rated voltage 35 V on samples of solid tantalum capacitors with manganese oxide cathode of three world producers. High temperature and high voltage applications of these capacitors are considered to be limited by ions diffusion and field crystallization mechanisms [1 to 6]. Crystalline oxide starts the recrystallization at temperature above 400 K without electric field. In electric field the recrystallization of tantalum pent-oxide can start at temperature as low as 400 K. Tantalum capacitor is here considered as a Metal – Insulator – Semiconductor (MIS) structure. I-V characteristics in normal and reverse mode were measured for temperatures 300 and 400 K. Further, the variations of leakage current during the thermal annealing were measured with time in the presence and absence of the external electric field, and evaluated. From these experiments information was received concerning the leakage current conduction mechanism. The leakage current values increase after temperature annealing at 400 K at rated voltage for 550 hours for some samples by up to 2 orders of magnitude. During annealing the drift-diffusion process is affected by concentration gradient of ions near Ta2O5–MnO2 interface. This paper documents the dependence of electron and ion transport parameters of tantalum capacitors on the particular technology used by three different world producers. Experiments were started with measurement of I-V characteristics at temperature 300 K and theirs analysis.

Tantalum capacitor, Ion diffusion, Stability, Leakage current

KUPAROWITZ, M.

2013

25. 9. 2013

Noordwijk, Nizozemí

978-5-7526-0597-0

https://escies.org/webdocument/showArticle?id=984&groupid=6

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