Transport analysis of filamentary dielectric breakdown model for metal-oxide-semiconductor tunnel structures

The current-voltage characteristics of n/sup +/ poly-Si/SiO/sub 2//p-Si tunnel structures containing nano-scale filaments embedded in ultra-thin oxide layers are analyzed using a 3D quantum mechanical scattering calculation. We find that the filaments act as highly efficient localized conduction paths and can lead to dramatic increases in current densities. By using progressively larger filaments, we can reproduce a range of stress-induced behavior found in experimental current-voltage characteristics, including quasi-breakdown and breakdown. We also find that at below flat-band, the current densities in structures with long filaments are greatly enhanced by resonant tunneling through states identified as quantum dots, and that this current enhancement is highly temperature dependent.