Interface trap and oxide charge generation under negative bias temperature instability of p-channel metal-oxide-semiconductor field-effect transistors with ultrathin plasma-nitrided SiON gate dielectrics

Zhu Shiyang

Nakajima Anri

Ohashi Takuo

Miyake Hideharu

Journal of Applied Physics

The interface trap generation (Δ Nit) and fixed oxide charge buildup (Δ Not) under negative bias temperature instability (NBTI) of p -channel metal-oxide-semiconductor field-effect transistors (p MOSFETs) with ultrathin (2 nm) plasma-nitrided SiON gate dielectrics were studied using a modified direct-current-current-voltage method and a conventional subthreshold characteristic measurement. Different stress time dependences were shown for Δ Nit and Δ Not. At the earlier stress times, Δ Nit dominates the threshold voltage shift (Δ Vth) and Δ Not is negligible. With increasing stress time, the rate of increase of Δ Nit decreases continuously, showing a saturating trend for longer stress times, while Δ Not still has a power-law dependence on stress time so that the relative contribution of Δ Not increases. The thermal activation energy of Δ Nit and the NBTI lifetime of p MOSFETs, compared at a given stress voltage, are independent of the peak nitrogen concentration of the SiON film. This indicates that plasma nitridation is a more reliable method for incorporating nitrogen in the gate oxide.

eng

American Institute of Physics

Copyright (c) 2005 American Institute of Physics.

[ISSN] 0021-8979

[DOI] 10.1063/1.2138372

[NCID] AA00693547

[DOI] http://dx.doi.org/10.1063/1.2138372