Charge Carriers Transport and Noise of Niobium Capacitors

Charge Carriers Transport and Noise of Niobium Capacitors

Paper in proceedings (conference paper)

A charge carriers transport mechanism and low frequency noise analysis has been performed on niobium capacitors to determine the mechanism of current flow and current noise sources, both in normal and reverse directions. The model of this MIS structure can be used to give a physical interpretation of the niobium capacitor characteristics and temperature dependences. In normal mode the V.A. characteristic can be approximated by Poole-Frenkel emission. In reverse mode two regions can be distinguished with respect to applied voltage. For applied voltage less than 0.5 V the V.A. characteristic can be approximated by exponential dependence of current on applied voltage. The noise spectral density varies approximately with the square of the leakage current, but it was frequently observed that the noise spectral density is related to the “excess” component of the leakage current. This excess current is most likely to be localised in discrete regions, flaws or defects. The temperature dependence of leakage current is also of an exponential form. The noise spectral density is 1/f in normal operation mode. Noise and transport characteristics are similar to that of tantalum capacitors.

A charge carriers transport mechanism and low frequency noise analysis has been performed on niobium capacitors to determine the mechanism of current flow and current noise sources, both in normal and reverse directions. The model of this MIS structure can be used to give a physical interpretation of the niobium capacitor characteristics and temperature dependences. In normal mode the V.A. characteristic can be approximated by Poole-Frenkel emission. In reverse mode two regions can be distinguished with respect to applied voltage. For applied voltage less than 0.5 V the V.A. characteristic can be approximated by exponential dependence of current on applied voltage. The noise spectral density varies approximately with the square of the leakage current, but it was frequently observed that the noise spectral density is related to the “excess” component of the leakage current. This excess current is most likely to be localised in discrete regions, flaws or defects. The temperature dependence of leakage current is also of an exponential form. The noise spectral density is 1/f in normal operation mode. Noise and transport characteristics are similar to that of tantalum capacitors.

Charge carriers transport, leakage current, noise, niobium capacitors

Charge carriers transport, leakage current, noise, niobium capacitors

ŠIKULA, J., PAVELKA, J., GRMELA, L., DOBIS, P., ZEDNÍČEK, T.

20.10.2002

Electronic Components Institute Internationale Ltd.

Swindon, England

CARTS-EUROPE 2002 Proceedings, 16th European Passive Components Conference

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