Impact strain engineering on gate stack quality and reliability

Strain engineering based on either a global approach using high-mobility substrates or the implementation of so-called processing-induced stressors has become common practice for 90 nm and below CMOS technologies. Although the main goal is to improve the performance by increasing the drive current, other electrical parameters such as the threshold voltage, the multiplication current, the low frequency noise and the gate oxide quality in general may be influenced. This paper reviews the impact of different global and local strain engineering techniques on the gate stack quality and its reliability, including hot carrier performance, negative bias temperature instabilities, time dependent dielectric breakdown and radiation hardness. Recent insights will be discussed and the influence of different strain engineering approaches illustrated.     

Performance and Reliability of Strained-Silicon nMOSFETs With SiN Cap Layer

A complete comparison of performance and reliability between polysilicon gate/SiON oxide nMOSFETs with and without SiN cap layer is presented. The uniaxial tensile strain induced by the cap layer causes an improvement in the channel current drive capability without degrading the noise performance. The gain in the transconductance, for the strained devices, was found to decrease for increasing channel lengths and for higher channel fields. Similar robustness against hot carrier stress, bias-temperature instability, and time to breakdown were found between strained and unstrained-silicon devices, confirming the advantages of strain technology     

Genetic regulation of trypsin inhibitory activity in soybean flour

Many biochemical and molecular details are available for soybean seed proteinase inhibitors, but little is known about the quantitative regulation of structural genes. In order to fill this gap, a complete set of diallel crosses was made between inbred lines characterised by the same inhibitor array coupled with a different inhibitor content in the raw flour. The Hayman analysis revealed the presence of different regulatory elements in the parental lines, giving rise to both additive and dominance variation. Dominant alleles were found to decrease the trypsin inhibitory activity (TI activity) shown by the raw flours and appeared to have higher frequencies than recessive alleles. Significant maternal effects were also detected, particularly in crosses of low‐TI activity female × high‐TI activity male; maternal effects strengthened the role of the regulatory genes transferred by the female parent to the hybrid. Data fitted the simple additive–dominance model with genes independent in both action and distribution. Narrow and broad heritability values were 54% and 82% respectively, thus indicating the feasibility of lowering TI activity through selection. © 2000 Society of Chemical Industry     

Thymosin β4 Is an Endogenous Iron Chelator and Molecular Switcher of Ferroptosis

Thymosin β4 (Tβ4) was extracted forty years agofrom calf thymus. Since then, it has been identified as a G-actin binding protein involved in blood clotting, tissue regeneration, angiogenesis, and anti-inflammatory processes. Tβ4 has also been implicated in tumor metastasis and neurodegeneration. However, the precise roles and mechanism(s) of action of Tβ4 in these processes remain largely unknown, with the binding of the G-actin protein being insufficient to explain these multi-actions. Here we identify for the first time the important role of Tβ4 mechanism in ferroptosis, an iron-dependent form of cell death, which leads to neurodegeneration and somehow protects cancer cells against cell death. Specifically, we demonstrate four iron²⁺ and iron³⁺ binding regions along the peptide and show that the presence of Tβ4 in cell growing medium inhibits erastin and glutamate-induced ferroptosis in the macrophage cell line. Moreover, Tβ4 increases the expression of oxidative stress-related genes, namely BAX, hem oxygenase-1, heat shock protein 70 and thioredoxin reductase 1, which are downregulated during ferroptosis. We state the hypothesis that Tβ4 is an endogenous iron chelator and take part in iron homeostasis in the ferroptosis process. We discuss the literature data of parallel involvement of Tβ4 and ferroptosis in different human pathologies, mainly cancer and neurodegeneration. Our findings confronted with literature data show that controlled Tβ4 release could command on/off switching of ferroptosis and may provide novel therapeutic opportunities in cancer and tissue degeneration pathologies.     

Cross‐correlation‐based trans‐impedance amplifier for current noise measurements

This work proposes a cross‐correlation‐based trans‐impedance amplifier for current noise measurements in the low‐frequency range. The proposed solution is compared with the classical cross‐correlation trans‐impedance amplifier showing a lower background noise. Furthermore, a three‐step measurement method, based on the new trans‐impedance amplifier, is proposed to cancel the residual background noise. SPICE simulations and noise measurements performed on prototype circuits demonstrate the validity of the proposed approach. Copyright © 2008 John Wiley & Sons, Ltd.     

Detection and Classification of Single-Electron Jumps in Si Nanocrystal Memories

In this paper, we report a purposely designed instrumentation and a jump detection procedure for the measurement of single-electron phenomena in solid-state nonvolatile memories based on a silicon nanocrystal floating gate metal-oxide-semiconductor field-effect transistor. The stepwise evolution of the drain current of a memory cell after a ldquowriterdquo operation is monitored by means of a purposely designed low-noise acquisition system with a bandwidth of up to 10 kHz. The advantage of the measurement system background noise and bandwidth over a traditional semiconductor parameter analyzer performance is evident in the detection and classification of single-electron events.     

Enhanced sensitivity cross-correlation method for voltage noise measurements

Ultralow noise measurements often require the application of signal processing and correction techniques to go beyond the noise performances of front-end amplifiers. In this paper, a new method for the voltage noise measurement is proposed, which allows, at least in principle, the complete elimination of the noise introduced by the amplifiers used for the measurements. This is obtained by resorting to the conventional cross-correlation technique for the elimination of the contribution of the equivalent input voltage noise of the amplifiers and by using a new three-step-measurement procedure that exploits different amplifier-configuration measurements in order to subtract the contribution of the equivalent input current noise of the amplifiers.     

Joint spatial analysis of gastrointestinal infectious diseases

A major obstacle in the spatial analysis of infectious disease surveillance data is the problem of under-reporting. This article investigates the possibility of inferring reporting rates through joint statistical modelling of several infectious diseases with different aetiologies. Once variation in under-reporting can be estimated, geographic risk patterns for infections associated with specific food vehicles may be discerned. We adopt the shared component model, proposed by Knorr-Held and Best for two chronic diseases and further extended by (Held L, Natario I, Fenton S, Rue H, Becker N. Towards joint disease mapping. Statistical Methods in Medical Research 2005b; 14: 61-82) for more than two chronic diseases to the infectious disease setting. Our goal is to estimate a shared component, common to all diseases, which may be interpreted as representing the spatial variation in reporting rates. Additional components are introduced to describe the real spatial variation of the different diseases. Of course, this interpretation is only allowed under specific assumptions, in particular, the geographical variation in under-reporting should be similar for the diseases considered. In addition, it is vital that the data do not contain large local outbreaks, so adjustment based on a time series method recently proposed by (Held L, H?hle M, Hofmann M. A statistical framework for the analysis of multivariate infectious disease surveillance data. Statistical Modelling 2005a; 5: 187-99) is made at a preliminary stage. We will illustrate our approach through the analysis of gastrointestinal diseases notification data obtained from the German infectious disease surveillance system, administered by the Robert Koch Institute in Berlin.