Significance of Breakdown Location on Post-Breakdown Transient and MOSFET Degradation

The breakdown (BD) location or the position of a percolation path in the channel of a metal-oxide-semiconductor field-effect transistor (MOSFET) has been found to be an important parameter controlling progressive breakdown (PBD), which is a critical BD phenomenon in ultrathin gate dielectrics. As a result, the post-BD gate leakage current degradation rate (dl_g/dt) depends strongly on the BD location, in which a BD MOSFET with an initial percolation path located near the center of the channel could have a dl_g/dt of 1-2 orders of magnitude smaller than that near the source/drain (S/D). Our results further suggest that dl_g/dt of narrow MOSFETs will be more severe than that of wide MOSFETs, due to not only the shorter channel length, but also other gate dielectric BD induced microstructural damages and defects