Explanation of nMOSFET substrate current after hard gate oxide breakdown

The origin of the substrate current in nMOSFET after hard gate oxide breakd own is studied as a function of the breakdown position. The breakdown path is modeled by a narrow (similar to5 nm diameter) inclusion of highly doped n-type silicon in SiO2. Device simulations excellently reproduce all post-b reakdown nMOSFET characteristics, including the substrate current behavior, for both gate-to-substrate and gate-to-extension breakdowns. The model als o identifies the origin of impact ionization and recombination observed in emission spectra. (C) 2001 Elsevier Science B.V. All rights reserved.