Dielectric breakdown in SiO2 via electric field induced attached hydrogen defects

We propose a new mechanism for dielectric breakdown in thin gate oxides. Using First Principles calculations, we have found a new meta-stable structure where an interstitial Hydrogen Radical attaches to a network Oxygen without breaking the Si-O bond (Att_Rad state). Calculations in an external electric field find that the energy of the Att_Rad state is reduced. A pair of such Att_Rad states is further stabilized when they form a dimer (Att-Dimer state). This electric field induced Att_Dimer state is thermally accessible for very thin oxides and can form a percolating path that may explain the phenomenon of soft breakdown.