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Presents a study that discussed selected design issues important to the operation of high-speed AlInAs/GaInAs heterojunction bipolar transistors. Description of the computational model of the study; Effect of the setback layer on the cutoff frequency; Effect of compositional grading.

Presents the experimental results of a molecular-beam epitaxy grown silicon/germanium silicide (Si/GeSi) p-n heterojunction. Condition of the current flow in the heterojunctions; Reason for the nonideal behavior of the Si/GeSi p-n heterojunction; Factor present at the Si/GeSi interface for the as-grown sample.

Presents a study which analyzed the electrical and chemical properties of the interfaces of thin oxides grown on strained Ge[subx]Si[sub1-x] layers using capacitance-voltage measurements and Auger electron spectroscopy. Materials and methods used; Approach in verifying the quality of the as-grown epilayer; List of electrical properties of the interface; Comparison of the electrical properties of oxides.

The paper presents a simulation study of the physics and performance of novel asymmetric tunneling solutions for the sub-100nm MOSFET technology. Two device structures have been investigated: Schottky Tunneling Source MOSFET and band-to-band P+-N+ Tunneling Source MOSFET. The Schottky MOSFET exhibits degraded Ion and subthreshold swing (in spite of improved DIBL). On the other hand, the novel PNPN MOSFET shows high Ion/Ioff and steep subthreshold behavior. [ABSTRACT FROM AUTHOR]

Discusses the electrical characterization of jet vapor deposited silicon nitride metal-nitride-semiconductor field-effect transistors (MNSFET) and conventional silicon dioxide metal oxide semiconductor field-effect transistors (MOSFET) having channel lengths down to 100 nanometer. Experimental methods; Pre-stress characterization of the MNSFET and MOSFET; Comparison between the hot-carrier degradation performance for MNSFET and MOSFET.

The material and electrical characteristics of ϵ-Cu3Ge as a contact metal were investigated. The samples were prepared by direct copper deposition on germanium wafers, followed by rapid thermal annealing. The ϵ-Cu3Ge formed at 400 °C has a resistivity of 6.8 μΩ · cm, which is lower than typical silicides for silicon CMOS. Cross-sectional transmission electron microscopy showed smooth germanide/germanium interface, with a series of nanovoids aligning close to the top surface. These voids are believed to be the results of Kirkendall effect arising from the different diffusion fluxes of copper and germanium. The specific contact resistivity of Cu3Ge, obtained from four-terminal Kelvin structures, was found to be as low as 8 × 10-8 Ω · cm² for p-type germanium substrate. This low resistivity makes Cu3Ge a promising candidate for future contact materials. [ABSTRACT FROM AUTHOR]

Mycotoxins such as the aflatoxins and deoxynivalenol (DON) are frequent contaminants of food. Aflatoxin B1 (AFB1) and DON affect the immune system and restrict growth; additionally AFB1 is carcinogenic. To date there are limited descriptive biomarker data concerning maternal exposures during pregnancy, and none on co-exposures to these mycotoxins. This survey was a cross-sectional assessment providing descriptive data on the concentrations of serum aflatoxin-albumin (AF-alb), urinary aflatoxin M1 (AFM1), and urinary DON for 98 pregnant women from Egypt, in relation to diet and socioeconomic status, during the third trimester. AF-alb was detected in 34 of 98 (35%) samples, geometric mean (GM) of positives = 4.9 pg AF-lys mg(-1) albumin (95% confidence interval (CI) = 4.1-5.8 pg mg(-1)), and AFM1 in 44 of 93 (48%) samples, GM of positives = 19.7 pg mg(-1) creatinine (95%CI = 14.8-26.3 pg mg(-1)). AF-alb and AFM1 levels were positively correlated (R = 0.276, p = 0.007). DON was detected in 63 of 93 (68%), GM of positives = 2.8 ng mg(-1) (95%CI = 2.1-3.6 ng mg(-1)). Aflatoxin and DON biomarkers were observed in 41% of the subjects concurrently. The frequency and level of these biomarkers in Egyptian women were modest compared with known high-risk countries. However, this study represents the first biomarker survey to report on the occurrence of DON biomarkers in an African population, in addition to the co-occurrence of these two potent mycotoxins. This combined exposure may be of particular concern during pregnancy given the potential of toxin transfer to the foetus.