Recombination lifetime profiling in very thin Si epitaxial layersused for bipolar VLSI

A recently proposed measurement technique (P. Spirito and G. Cocorullo, IEEE Trans. Electron Devices, vol.ED-32, no.9, p.1708-13, 1985) to evaluate the recombination lifetime along epitaxial layers is used to characterize the quality of very thin Si epitaxial layers used for bipolar technology. The experimental results show the ability of the technique to give accurate and detailed information on the quality of epilayers that could be useful in monitoring and improving the growth process. The experimental results show that the lifetime values in thin epilayers are not correlated with doping profiles in the same layers; moreover, they are only slightly dependent on different processes used to make the test devices     

Effective components of TORDIA cognitive–behavioral therapy for adolescent depression: Preliminary findings.

In this report, we conducted a secondary analysis of the Treatment of SSRI-Resistant Depression in Adolescents (TORDIA) study to explore the impact of specific cognitive–behavioral therapy (CBT) treatment components on outcome. In TORDIA, 334 youths (ages 12 to 18 years) with major depressive disorder who had failed to respond to an adequate course of selective serotonin reuptake inhibitor (SSRI) medication were randomized to a medication switch (either to an alternative SSRI or venlafaxine) with or without 12 weeks of adjunctive CBT. Participants who had more than 9 CBT sessions were 2.5 times more likely to have adequate treatment response than those who had 9 or fewer sessions. CBT participants who received problem-solving and social skills treatment components, controlling for number of sessions and other confounding variables, were 2.3 and 2.6 times, respectively, more likely to have a positive response. These preliminary findings underscore the importance of receiving an adequate number of sessions to attain an adequate clinical response. Finally, social skills and problem solving may be active elements in CBT for adolescent depression and should be considered in treatment by those working with seriously depressed youths. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New semiconductor active device: the conductivity-controlled transistor

A new semiconductor 3-terminal device has been realised in which a majority-carrier current, flowing in a N+-N-N+ structure, is controlled by a minority-carrier current supplied by a forward-biased P+-N junction. The properties of this device are presented and discussed in terms of a physical model.     

Reliability enhancement with the aid of transient infrared thermal analysis of smart Power MOSFETs during short circuit operation

The usage of novel measurement techniques enhances the capabilities of researchers and power device manufacturers to understand and address reliability problems in novel Smart Power Devices. Along this line of argument, this work describes a method to improve the reliability of the smart Power MOSFET devices by design. The design optimization process involves Silicon layout, interconnections, packaging and protection strategy as well. Accurate thermal transient analyses, made possible by the unique features of a custom infrared radiometric microscope experimental setup which allows dynamic temperature detection with a bandwidth of 1 MHz over the chip area, indicated the way to minimize peak temperature and to verify the effect of the optimization.     

An improved test structure for recombination lifetime profilemeasurements in very thick silicon wafers

A new test structure for recombination lifetime profile measurements has been designed and applied, for the first time, to the characterization of very thick bulk silicon wafers. The capability of the new test device to reject parasitic effects, affecting the reliability of the measure in bulk wafers, is shown by means of two-dimensional (2-D) simulations and experimental results. The proposed device has permitted the characterization of two P-type silicon bulk samples. For the first time a clear experimental evidence that the dopant acts as a recombination center has been found in this kind of material     

Design of IGBT with integral freewheeling diode

A new power structure integrating a freewheeling diode in the termination region of a punch-through (PT) insulated gate bipolar transistor (IGBT) is presented. The proposed solution requires virtually no silicon area penalty with respect to a standard IGBT. Static and dynamic experimental results show the correct behavior of both IGBT and freewheeling diode. Further, it is shown that the lateral diode surrounding the multicellular IGBT can support IGBT direct current with low on-state voltage drop. The operation mechanisms of the composite structure and design techniques to improve structure dynamic behavior are investigated through two-dimensional numerical device simulations     

Brief motivational interviewing in a hospital setting for adolescent smoking: A preliminary study.

This study tested the feasibility and efficacy of a brief smoking intervention for adolescents in a hospital seeing. Forty adolescent patients were randomized to receive either brief advice or a motivational interview, a nonconfrontational therapeutic intervention. Feasibility of brief smoking interventions with teen patients was supported by high rates of recruitment, retention, and quit attempts, and long periods of continuous abstinence. Although between-groups differences on smoking measures were not significant at 3-month follow-up, an effect size of h?=?.28 was noted. The sample showed significant decreases in smoking dependence and number of days smoked. Baseline stage of change, smoking rate, and depression were significant prospective predictors of smoking outcome. Implications for smoking intervention research with adolescents are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamic light scattering study of fine semiflexible fibrin networks

Fine fibrin networks have been investigated using the dynamic light scattering (DLS) technique. At the shortest delay times, t, the dynamic structure factor s(q,t) is found to depend on time according to an exponential function and, at intermediate delay times (up to 1 ms), to a stretched exponential. At longer times (t > 1 ms), a progressively increasing deviation from the stretched exponential behaviour has been observed. These results are in agreement with the theoretical predictions of a recently forwarded model for semiflexible polymers in semidilute solutions [K. Kroy and E. Frey, Physical Review E 55 (1996) p. 3092.], despite the fact that fibrin networks are made up of crosslinked branched polymers. The model, moreover, allows the calculation from the initial decay rate gamma q(0) of the average diameter of the fibrin fibres, a. The value of a = 30 +/- 2 nm, at fibrinogen concentration c(f) = 1676 nM and ionic strength 0.5, fits well into the data reported in electron microscopy studies. A concentration dependence of the average diameter of the fibrin fibres has been observed which saturates at the highest concentrations. The diameter of fibrin fibres is an important component in determining the physical properties of the fibrin networks, since the radial growth of fibrin fibres is limited by twisting during protofibrils aggregation. Our results indicate the importance of taking into account intrinsic semiflexibility in studying the physical properties of 'real' polymers and emphasize the high sensitivity of the DLS technique to investigate biological polymers also at the lowest concentrations where the systems are very fragile.