Effective Dielectric Thickness Research Articles

The electrical characteristics of MBE n-Hg1–x Cd x Te (x = 0.29–0.31) MIS structures with sharp inhomogeneities in composition

The effect of regions with periodic sharp 48–54 nm thick inhomogeneities in composition on the electrophysical characteristics of MIS structures based on graded-gap n-Hg1–x Cd x Te (x = 0.29–0.31) grown by molecular-beam epitaxy is studied. It is found that major electro-physical and photo-electrical characteristics are qualitatively similar for MIS structures based on n-Hg1–x Cd x Te with sharp inhomogeneities in composition (barriers) and without “barriers”. It is shown that the electrical characteristics are mostly affected by the “barrier regions” located close to the insulator – semiconductor interface. This effect is manifested in an increase of the effective dielectric thickness, which can be due to the fact that the regions of enhanced composition form potential barriers for electrons, and in a decrease in the relaxation time of non-equilibrium carriers due to recombination at the boundaries of the regions with sharp changes in composition.

Effects of an ultrathin Si passivation layer on the interfacial properties of RF-sputtered HfYOx on n-GaAs substrates

In this paper, we present the results of our investigations on the effects of an ultrathin Si interface control layer on the electrical properties of MOS capacitors fabricated using RF-sputtered HfYOx as the dielectric on n-GaAs. X-ray photoelectron spectroscopy analysis shows that suppression of low-k interfacial layer formation is accomplished with the introduction of an ultrathin Si interface control layer. I–V and C–V characteristics of Al/HfYOx/Si/n-GaAs MOS capacitors with an effective dielectric thickness of ∼1.8 nm show superior electrical properties. A density Dit of (1–2) × 1012 eV−1 cm−2 of low mid-gap interface states with low frequency dispersion (<3.3%) and a low border trap density of 1.7 × 1012 cm−2 have been obtained.

Estimating effective dielectric thickness for capacitors with extrinsic defects by a statistical method

Simulated capacitor breakdown voltage data are fit to a mixture of two Weibull distributions using the method of maximum likelihood. The dielectric thickness of extrinsic capacitors is estimated as a part of a mixture distribution, allowing simultaneous prediction of failure times using both intrinsic and extrinsic failures. Confidence intervals on the reliability parameters and the 10 year FIT rate at 5 V are successfully estimated using the delta method. The same approach is applied to a real data set with similar results.

Optimized dual temperature pulsed laser deposition of TiO2 to realize MTOS (metal-TiO2–SiO2–Si) capacitors with ultrathin gate dielectric

In this work, metal-TiO2–SiO2–Si (MTOS) capacitors have been fabricated where the TiO2 layers have been deposited by the pulsed laser deposition technique followed by annealing at different temperatures. MTOS devices with an effective dielectric thickness (EDT) as low as 1.6 nm and very low leakage current have been realized by using a two-step deposition process in which a buffer layer of TiO2 has first been deposited at 300 °C. This was followed by deposition and annealing of TiO2 at 750 °C. It has also been shown that the annealing temperature plays a significant role in determining the EDT of the dielectric film as well as the electrical characteristics of the MTOS capacitors.

Effective Dielectric Thickness Scaling for High-K Gate Dielectric Mosfets

AbstractIt has been shown recently that the short channel performance worsens for high-K dielectric MOSFETs as the physical thickness to the channel length ratio increases, even when the effective oxide thickness (EOT) is kept identical to that of SiO2. In this work we have systematically evaluated the effective dielectric thickness for different Kgate to achieve targeted threshold voltage (Vt), drain-induced barrier lowering (DIBL) and Ion/Ioff ratio for different technology generations down to 50 nm using 2-Dimensional process and device simulations. Our results clearly show that the oxide thickness scaling for high-K gate dielectrics and SiO2 follow different trends and the fringing field effects must be taken into account for estimation of effective dielectric thickness when SiO2 is replaced by a high-K dielectric.

Endfire tapered slot antennas on dielectric substrates

Endfire tapered slot antennas are suitable for many integrated circuit applications, imaging and phased arrays. We report on an investigation of single elements of such antennas, including slots which are exponentially tapered (Vivaldi), linearly tapered (LTSA) and constant width (CWSA). For antennas of all types, a good general agreement is obtained for curves of beamwidth versus length, normalized to wavelength, when one compares the data with that for traveling-wave antennas published by Zucker. An important condition for this agreement is that the effective dielectric thickness, defined in the text, is in a certain optimum range. This condition is qualitatively explained in terms of the theory for traveling-wave antennas.

Study of sandwich cathodes with non-uniform dielectric thickness

A model of metal-dielectric-metal thin-film systems is created in the paper with the Monte Carlo method. In the model the migration of atoms during the deposition of metal electrodes is taken into account. In this way we obtained for description of non-uniformity of dielectric thickness the expression based on the Gaussian distribution function. The problem was solved in the one-dimensional case by means of a computer. Expressions for the effective dielectric thickness obtained from the capacitance measurements and for the thickness evaluated from the volt-ampere characteristics of the tunnel current were found.

A‐C Properties of Anodic Oxide Films on Silicon

Low resistivity (∼0.02 ohm cm), (111)‐oriented, p‐type silicon slices were anodized in a solution of in ethylene glycol containing 2% water, and the dielectric behavior of the system has been studied. It was found that the reciprocal capacitance decreased proportionally to the square root of time during which the sample was immersed in a measurement electrolyte. Denning a “diffusion constant,” , it was found that was not affected by the pH of the measurement electrolyte but increased (i) with the water content of the electrolyte, (ii) with temperature, and (iii) with anodic bias. An activation energy of 0.66 ev has been determined between 0° and 75 °C. It is suggested that water, after entering the anodic oxide, dissociates into hydroxyl groups which migrate into the oxide and cause the effective dielectric thickness to decrease. Partial dehydration was possible by annealing or by evacuation. The frequency dependence of the capacitance, when measured in an electrolyte of low water content, (i) increased with film thickness for oxide layers formed at the same current density, and (ii) decreased with increasing formation current density for constant film thickness.