Atomic Scale Defects Associated with the Negative Bias Temperature Instability
Jason P. Campbell, P. M. Lenahan
We utilize magnetic resonance measurements to identify the fundamental atomic-scale defect structures involved in the negative bias temperature instability. In gate stacks composed of pure silicon dioxide, we find a degradation mechanism directly involving Pb0 and Pb1 defect centers (silicon dangling bond defects in which the silicon is back-bonded to three other silicon atoms precisely at the silicon/silicon dioxide interface). We observe that, in pure SiO2-based devices, the generation of these interface defects is catalyzed by the generation of E center bulk dielectric defects (silicon dangling bond defects in which the silicon is back-bonded to oxygen atoms). These observations are the first to indicate a prominent role for E centers in the negative bias temperature instability for pure silicon dioxide based devices. In gate stacks composed of plasma-nitrided oxides, we identify a degradation mechanism which is dominated by the generation of a new defect center which we identify as a KN center. KN centers are silicon dangling bond defects in which the silicon is back-bonded to three nitrogen atoms with second nearest neighbor atoms likely including oxygen. KN centers are located within the amorphous silicon oxy-nitride and electrically behave as both interface states as well as bulk dielectric defects (serve as both recombination and tunneling sites). In these plasma nitrided gate stacks, the negative bias temperature instability does not involve the generation of Pb0, Pb1, or E centers. These collective observations provide a useful fundamental understanding with which to critically examine the current and future negative bias temperature instability framework.
Bias Temperature Instability for Devices and Circuits
and Lenahan, P.
Atomic Scale Defects Associated with the Negative Bias Temperature Instability, Bias Temperature Instability for Devices and Circuits, Springer Science+Business Media LLC, New York, NY
(Accessed May 29, 2023)