Gate oxide degradation due to trapping of positive charges during Fowler-Nordheim stress at low electron fluence: a rigorous model

摘要

Gate oxide degradation has been theoretically investigated in n/sup +/-polySi-gate metal-oxide-semiconductor (MOS) capacitors during low fluence (/spl les/0.01 C/cm/sup 2/) Fowler-Nordheim (FN) injection from (100) n-Si at a wide range (6-12 MV/cm) of oxide electric field. Oxide thicknesses were 22, 27 and 33 nm. Trapped positive charge induced oxide degradation is modeled with a new coupled trapping dynamics based on tunneling electron initiated band to band impact ionization (BTBI) and trap ionization (TTBI) in the oxide gap. In addition, we have compared the degradation during and FN stress at constant current and constant gate voltage.