Soft breakdown in very thin Ta sub(2)O sub(5) gate dielectric layers

The time-dependent dielectric breakdown of metal-oxide-semiconductor capacitors with 6 nm and 8 nm Ta sub(2)O sub(5) gate dielectric layers is investigated. During constant voltage stress of the capacitors, a small increase in the time-dependent gate current is observed, followed by the occurrence o...

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Bibliographic Details
Published in:Solid-state electronics 2000-03, Vol.44 (3), p.521-525
Main Authors: Houssa, M, Mertens, P W, Heyns, M M, Jeon, J S, Halliyal, A, Ogle, B
Format: Article
Language:English
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Summary:The time-dependent dielectric breakdown of metal-oxide-semiconductor capacitors with 6 nm and 8 nm Ta sub(2)O sub(5) gate dielectric layers is investigated. During constant voltage stress of the capacitors, a small increase in the time-dependent gate current is observed, followed by the occurrence of erratic fluctuations. After the occurrence of such a small jump, the current-voltage characteristics reveal increased gate current in the low gate voltage region, as compared to the current-voltage characteristics of fresh (unstressed) devices. In addition the gate current is shown to behave like a power law of the applied gate voltage. All above features are characteristics of the so-called soft breakdown event which has been previously reported for ultra-thin SiO sub(2) layers.
ISSN:0038-1101