Degradation and hard breakdown transient of thin gate oxides in metal-SiO2-Si capacitors: Dependence on oxide thickness

We have investigated the dynamics of hard intrinsic dielectric breakdown of gate oxide layers with thickness between 35 and 5.6 nm in n(+) polycrystal line Si-SiO2-Si metal/oxide/semiconductor capacitors after constant voltage Fowler-Nordheim stress. The buildup of defects in the oxide during the deg radation phase was monitored by quasi static C-V measurements. The dynamics of the final breakdown event was followed with high time resolution, allow ing to measure voltage, current, and power versus time during the breakdown transient. Transmission electron microscopy data quantifying the damage pr oduced during this transient are reported. Finally, we propose a phenomenol ogical model concerning the dynamics of breakdown with model parameters adj usted on the basis of the experimental data. (C) 1999 American Institute of Physics. [S0021-8979(99)07322-3].