Interaction of molecular hydrogen with trapped hole E' centers in irradiated and high field stressed metal/oxide/silicon oxides Dependence of radiationinduced interface traps on gate Al thickness in metal/SiO2/Si structures We report electron spin resonance (ESR) measurements of E' -center (a "trivalent silicon" center in SiOz) density as well as capacitance versus voltage (C-V) measurements on y-irradiated metal! oxide/silicon (MOS) structures. We also report a considerable refinement of earlier ESR measurements of the dependence of radiation-induced P b -center (a "trivalent silicon" center at the SiiSiO z interface) occupation as a function of the Fermi level at the SiiSiO z interface. These measurements indicate that the P b centers are neutral when the Fermi level is at mid-gap. Since the P b centers are largely responsible for the radiation-induced interface states, one may take L1 V mg Cox / e (where L1 V mg is the "mid-gap" C-V shift, Cox is the oxide capacitance, and e is the electronic charge) as the density of holes trapped in the oxide. We find that radiation-induced E' density equals L1 V mg Cox / e in oxides grown in both stream and dry oxygen. Etch-back experiments demonstrate that the E' centers are concentrated very near the SilSi0 2 interface (as are the trapped holes). Furthermore, we have subjected irradiated oxide structures to a sequence of isochronal anneals and find thatthe E ' density and L1 V mg annealing characteristics are virtually identical. We conclude that theE' centers are largely responsible for the deep hole traps in thermal Si0 2 on silicon. This observation coupled with observations regarding theP b center indicates that two intrinsic centers, both involving silicon atoms lacking one bond to an oxygen atom, are largely responsible for the two electrically significant aspects of radiation damage in MOS devices: charge buildup in the oxide and interface-state creation at the SiiSiO z interface.

A physically based methodology is developed for modeling the behavior of electrical circuits containing nonideal ferroelectric capacitors. The methodology is illustrated by modeling the discrete ferroelectric capacitor as a stacked dielectric structure, with switching ferroelectric and nonswitching dielectric layers. Electrical properties of a modified Sawyer–Tower circuit are predicted by the model. Distortions of hysteresis loops due to resistive losses as a function of input signal frequency are accurately predicted by the model. The effect of signal amplitude variations predicted by the model also agree with experimental data. The model is used as a diagnostic tool to demonstrate that cycling degradation, at least for the sample investigated, cannot be modeled by the formation of nonswitching dielectric layer(s) or the formation of conductive regions near the electrodes, but is consistent with a spatially uniform reduction in the number of switching dipoles.

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