Polarity dependence of charge to breakdown and interface state generation of oxynitride gate dielectrics prepared by rapid thermal processing

MOS devices were fabricated with dry thermal oxides, nitrided oxides and annealed nitrided oxides. The anneals were performed in O/sub 2/ or N/sub 2/ ambients using rapid thermal processing. Charge to breakdown, Q/sub bd/, and interface state generation, Delta D/sub it/, for these devices were studied using Fowler-Nordheim electron injection. The gate bias polarity dependence of Q/sub bd/ and Delta D/sub it/ was investigated. A model is proposed to explain the observed dependence of these quantities on the polarity of injection and process parameters.<>     

Characterization and reliability of dual high-k gate dielectric stack (poly-Si-HfO/sub 2/-SiO/sub 2/) prepared by in situ RTCVD process for system-on-chip applications

We investigate for the first time the possibility of integrating chemical vapor deposition (CVD) HfO/sub 2/ into the multiple gate dielectric system-on-a-chip (SoC) process in the range of 6-7 nm, which supports higher voltage (2.5-5 V operation/tolerance). Results show that CVD HfO/sub 2/-SiO/sub 2/ stacked gate dielectric (EOT =6.2 nm) exhibits lower leakage current than that of SiO/sub 2/ (EOT =5.7 nm) by a factor of /spl sim/10/sup 2/, with comparable interface quality (D/sub it//spl sim/1/spl times/10/sup 10/ cm/sup -2/eV/sup -1/). The presence of negative fixed charge is observed in the HfO/sub 2/-SiO/sub 2/ gate stack. In addition, the addition of HfO/sub 2/ on SiO/sub 2/ does not alter the dominant conduction mechanism of Fowler-Nordheim tunneling in the HfO/sub 2/-SiO/sub 2/ gate stack. Furthermore, the HfO/sub 2/-SiO/sub 2/ gate stack shows longer time to breakdown T/sub BD/ than SiO/sub 2/ under constant voltage stress. These results suggest that it may be feasible to use such a gate stack for higher voltage operation in SoC, provided other key requirements such as V/sub t/ stability (charge trapping under stress) can be met and the negative fixed charge eliminated.     

Hole tunneling current through oxynitride/oxide stack and the stackoptimization for p-MOSFETs

A systematic study on hole-tunneling current through both oxynitride and oxynitride/oxide (N/O) stack is for the first time presented based on a physical model. The calculations are in good agreement with the available experimental data. With a given equivalent oxide thickness (EOT), and under typical operating gate voltages (|Vg|<2 V), hole-tunneling current (essentially the gate current) is found to be lowest through the oxynitride or N/O stack with ~33% of nitrogen (N). An optimized N/O stack structure with 33% (atomic percentage) nitrogen and with a 3 Å oxide layer for keeping acceptable channel interface quality is proposed to project the N/O gate dielectrics scaling limit using in MOSFETs     

Image transmission in multicore-fiber code-division multiple-accessnetworks

Two-dimensional (2-D) signature patterns, so-called optical orthogonal signature pattern codes (OOSPCs), were previously proposed to encode binary digitized image pixels in optical code-division multiple-access (CDMA) networks with “multicore” fiber. The new technology enables parallel transmission and simultaneous access of 2-D images in a multiple-access environment. However, previous work on OOSPCs assumed that the weight of every signature pattern in a code set was the same. In this paper, we construct and analyze a new family of OOSPCs without this assumption. Since the performance of a signature pattern varies with its code weight, our approach is useful for optical CDMA networks with a multiple performance requirement     

Dynamic NBTI of p-MOS transistors and its impact on MOSFET scaling

For the first time, a dynamic negative bias temperature instability (DNBTI) effect in p-MOSFETs with ultrathin gate oxide (1.3 nm) has been studied. The interface traps generated under NBTI stressing corresponding to p-MOSFET operating condition of the "high" output state in a CMOS inverter, are subsequently passivated when the gate to drain voltage switches to positive corresponding to the p-MOSFET operating condition of the "low" output state in the CMOS inverter. Consequently, this DNBTI effect significantly prolongs the lifetime of p-MOSFETs operating in a digital circuit, and the conventional static NBTI (SNBTI) measurement underestimates the p-MOSFET lifetime. A physical model is presented to explain the DNBTI. This finding has significant impact on future scaling of CMOS devices.     

Improved reliability characteristics of submicrometer nMOSFETs withoxynitride gate dielectric prepared by rapid thermal oxidation inN2O

Submicrometer MOSFETs with ultrathin oxynitride gate dielectric grown in pure N₂O ambient were studied. The peak mobility of oxynitride is 5% lower than that of control oxide. However, the oxynitride shows 10% less mobility degradation under high normal field. Compared with the control oxide device, the oxynitride device shows significantly less degradation under channel hot-electron stress. The lifetime of the oxynitride device is approximately one order of magnitude longer than that of the control oxide sample. Significant improvement of device reliability is due to the nitrogen incorporation during the oxidation process     

Detection of intrauterine illicit drug exposure by newborn drug testing. National Academy of Clinical Biochemistry

Identification of intrauterine drug-exposed newborns with toxicological screening may have benefits including close follow-up of the infant by both medical and social services. Applying specific written guidelines to select newborns for drug testing decreases bias and protects the physicians and hospitals involved. All drugs reported as positive should be confirmed by an appropriate second test. Urine and meconium testing are the best current options for identifying drug-exposed neonates. Urine testing sensitivity is low because of problems encountered in urine collections and the high thresholds used in current urine assays. The disadvantage to meconium testing is the increased labor and time required to work with this material. Testing of newborn hair is unlikely to be widely used until technically less demanding assays become available. Testing of amniotic fluid or gastric lavage is still in the developmental stages. Adopting lower urine assay thresholds for newborn samples would increase sensitivity and would be an appropriate modification of current methodologies.     

Analysis and design of watermarking algorithms for improved resistance to compression

We study the performance of robust digital watermarking approaches in the presence of lossy compression by introducing practical analysis methodologies. Correlation expressions between the embedded watermark and the extracted watermark are derived to determine the optimal watermarking domain to maximize data hiding rates for spread spectrum and quantization watermarking. It is determined both theoretically and through simulations that the embedding strategy, in addition to the transform used for lossy compression, dictate the optimal transform for watermarking. Through analytic comparisons, we develop a novel hybrid watermarking algorithm that exploits the best of both approaches for greater resilience to JPEG compression.     

Cognitive mediation of adult age differences in language performance.

Young (M?=?20 years) and old (M?=?68 years) adults completed language processing tasks, measures of working memory capacity (backward span and the n-back lag task), inhibitory efficiency (Stroop interference), and processing speed (color naming). Regression analyses revealed that each of the resource measures significantly predicted language performance and attenuated variance in language performance that would otherwise be attributed to age. When speed variance was entered into the equation first, the mediating influence of the inhibition and working memory measures remained significant. When speed and inhibition differences were controlled, the working memory measures could not reliably predict language performance. These results suggest that language performance differences may be fundamentally mediated by age differences in processing speed and inhibitory efficiency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low frequency of TEL/AML1 in adult acute lymphoblastic leukemia

Translocation (12;21)(p13;q22) is a recently characterized aberration in acute lymphoblastic leukemia, and results in the fusion of the TEL and the AML1 genes. It is the most common translocation in pediatric acute lymphoblastic leukemia (ALL), occurring in about one third of the cases. To determine the frequency of TEL/AML1 in adult ALL, we studied 4 cases of T lineage ALL and 26 cases of B lineage ALL. Only one positive case was identified, giving a very low frequency of 3.3%. In this patient, TEL/AML1 was still detectable in complete hematologic remission. The apparent age predilection of t(12;21) warrants further investigations.