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Negative Bias Temperature Instability (NBTI) is studied in p-MOSFETs having Decoupled Plasma Nitrided (DPN) gate oxides (EOT range of 12A O through 22A O ). Threshold voltage shift (∆V T ) is shown to be primarily due to interface trap generation (∆N IT ) and significant hole trapping (∆N OT ) has not been observed. ∆V T follows power-law time (t) dependence and Arrhenius temperature (T) activation. IntroductionNBTI is a serious reliability concern for p-MOSFETs [1]. Oxynitrides (required for suppressing boron penetration and gate leakage) show worse NBTI than control oxides and has attracted much attention [2][3][4][5]. It is important to correctly measure and extrapolate t evolution of ∆V T to accurately determine device lifetime. However, this extrapolation is complicated since (i) impact of delay time on measurement is not fully understood, (ii) ∆V T origin (∆N IT that predicts t

We have analyzed red and blue luminescence from porous silicon as a function of oxidation parameters and feature dimension determined with an atomic force microscope. We have found correlation between blue luminescence intensity and the increase in feature size caused by oxidation. We have further shown that blue luminescence, is identical, with respect to spectrum and fast decay, to that of high microelectronic quality SiO, grown on crystalline silicon using dry oxygen plus an organic chlorine compound. Thus, we conclude that blue luminescence originates from SiOZ film rather than from the silicon nanocrystals in the porous material. Intensity enhancement, as compared to SiO, on crystalline wafers, comes from the gigantic surface area of porous silicon.

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The effect of dielectric constant and barrier height on the WKB modeled tunnel currents of MOS capacitors with effective oxide thickness of 2.0 nm is described. We first present the WKB numerical model used to determine the tunneling currents. The results of this model indicate that alternative dielectrics with higher dielectric constants show lower tunneling currents than SiO 2 at expected operating voltages. The results of SiO 2 /alternative dielectric stacks indicate currents which are asymmetric with electric field direction. The tunneling current of these stacks at low biases decreases with decreasing SiO 2 thickness. Furthermore, as the dielectric constant of an insulator increased, the effect of a thin layer of SiO 2 on the current characteristics of the dielectric stack increases. Semiconductor Research Corporation (SRC Contract 132).

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Since nitrided oxides improve gate leakage at the expense of NBTI, one must optimize nitrogen concentration in oxinitride samples for reliable performance and reduced power dissipation. Here, we analyze wide range of NBTI stress data to develop a predictive model for gate leakage and first selfconsistent model for field acceleration within R-D framework. This model anticipates a novel design diagram for co-optimization of leakage and NBTI for arbitrary nitrogen concentration and effective oxide thickness.1. Introduction Since nitrided oxides (SiON) improve gate leakage (J G ) [1-6] at the expense of NBTI performance (∆V T ) [7,8], one must necessarily optimize N 2 concentration (%N) in gate-oxides for high-performance ICs. Despite its importance, however, a quantitative analysis of leakage/NBTI trade-off (as a function of %N), has never been reported and the question "Is cooptimization of NBTI/leakage possible at any %N?" has never been answered. In this paper, we simultaneously measure gate leakage and delay-free NBTI over broad range of stress-fields, stress-temperatures and %N, model gate leakage current (J G ) and NBTI degradation within a theoretically consistent framework (hole-assisted thermal generation of interface traps) of field-dependent R-D model, and conclude that although there is no optimum %N for NBTI/leakage, the reduction in J G at NBTI-limited %N (~15-25%, depending on failure criterion) can be significant and would reduce power dissipation without affecting NBTI-margin.2. Gate Leakage Comprehensive simulation [9] (which includes the effects of multi-subband electron/hole quantization, poly-depletion, etc.) of the measured J G -V G for both N-and PMOS (Fig. 1) was done to extract the model parameters as a function of %N (Fig. 2). We assume that any variation in the spatial-profile of nitrogen results only in second-order correction to calculated J G . Contrary to popular belief [2-6, 10], the oxide parameters do not scale linearly with %N. All the parameters have approximately a quadratic fit with %N. Here, effective oxide thickness (EOT) is obtained from simulation of CV, and physical thickness (T PHY ) and %N are determined by XPS [11]. These %N-dependent parameters are used to calculate J G (N,EOT) for arbitrary %N and EOT, as shown in Fig. 10b. -1.0 -0.5 0.0