Challenges in advanced semiconductor technology for high-performance and supercomputer applications

This article provides a review of the capabilities, future directions, and technology challenges for semiconductor chips and packages as they apply to high-performance and supercomputer applications. Semiconductor chip technology has resulted in dramatic device density improvements over the last 20 years. Scaling theory predicts that continued improvements will be possible if the technological problems associated with patterning, doping, interconnection, density, yield, and cost can be solved. The issues associated with these challenges are discussed. Finally, the packaging needs to support advanced chip technologies are reviewed.     

Psychotherapy as a professional relationship.

One explanation offered for the successes found in every system of psychotherapy is that there is in common a cordial therapist–client relationship. Moreover, because the therapist is trained in dealing with psychological problems, some have held that the therapist is a superior, more effective friend whose skills, particularly in empathic communication, might well be fostered in the general population. The research has not supported these assertions when therapists of many different orientations are compared or when the results of nonprofessional helpers are compared with those of professional psychotherapists. An analysis of the structures of informal and professional relationships demonstrates that they have quite distinctive properties. Specific advantages and disadvantages of professional and nonprofessional relationships are noted. It may be equally appropriate to attend to their differences as well as to their similarities and to consider those who may be helped only by professional interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Challenges in advanced semiconductor technology in the ulsl era for computer applications

This paper provides a review of the capabilities, future directions, and technology challenges for semiconductor chips and packages as they apply to high performance and supercomputer applications. Semiconductor chip technology has resulted in dramatic device density improvements over the last 20 years. Scaling theory predicts that continued improvements will be possible if the technological problems associated with patterning, doping, interconnection, density, yield, and cost can be solved. The issues associated with these challenges are discussed. Finally the packaging needs to support advanced chip technologies are reviewed.     

Can control and creativity coexist?

By necessity, corporate computing environments heavily restrict users in an attempt to limit corporate legal liability and to control cost and maintenance efforts. Academia, on the other hand, has long tolerated wide-ranging capabilities for users, all in the name of academic freedom. If corporations want employees to use technology creatively, it seems as if they should take a lesson or two from academia.     

A new MOS-gated power thyristor structure with turn-off achieved bycontrolling the base resistance

A new MOS-gated power thyristor structure, called the base-resistance-controlled thyristor (BRT), is described. In this structure, the turn-off of a thyristor with an N-drift region is achieved by reducing the resistance of the P-base region under MOS-gate control. In contrast with previous devices, a P-channel MOSFET integrated in the N-drift region is used for this purpose. It has been shown, by two-dimensional numerical simulations and experimental measurements on devices fabricated using a seven-mask process, that devices with 600-V forward blocking capabilities can be achieved with a forward drop close to that for a thyristor. The ability to turn off the thyristor current flow has been verified over a broad range of current densities     

Characteristics of the emitter-switched thyristor

The first experimental demonstration of 600-V emitter-switched thyristors fabricated using an IGBT (insulated-gate bipolar transistor) process sequence is reported. The forward drop is less than that for the IGBT, but larger than that for a thyristor by about 0.5 V due to the thyristor current flowing via the MOSFET channel. A unique characteristic observed for these devices, not exhibited by any previous MOS-gated thyristor structures, is gate-controlled current saturation even after thyristor latch-up. Switching tests were performed up to a current density of 1000 A/cm² on single-unit cells and the measured turn-off times were about 7 μs     

Small area deposition of Ge on Ge or GaAs substrates via the disproportionation of GeI2

Metallurgical and Materials Transactions B - The low temperature GeI2 disproportionation reaction was used to grow epitaxial germanium at 350°C selectively in small areas on germanium and GaAs...     

On alternative strategies for doing research in the management andsocial sciences

The author delineates a number of taxonomic approaches to classifying knowledge for research into management and social sciences and points out the need for yet higher order contributions, namely those which embed that which is known in more generalized theoretical frameworks. He also discusses research strategies that do not necessarily contribute to the objective of consolidating knowledge. Lastly, he comments on some of the pitfalls of each research strategy and the relative ease or difficulty in overcoming such pitfalls depending on the strategy chosen     

SiO2 gate insulator defects,spatial distributions,densities, types,and sizes

Standard IC processes, as well as those involving the use of ionizing radiation, such as x-ray lithography etc., result in the generation of bulk defects, and interface states in the gate insulator, or underlying substrate, respectively, of insulated gate field effect transistors. Bulk defects are believed to be present as positively and negatively charged electron and hole traps, respectively, as well as neutral hole and “large” and “small” neutral electron traps. This paper provides a perspective of the current state of knowledge about the spatial distributions of large bulk defects, their areal densities, sizes, possible interrelationships among them, and the special cases of defects created by ion implanted silicon and oxygen, where knock-on effects have been simulated. It appears that bulk defects may all have their origin in neutral hole traps, (so-called E′ centers) and that when the insulator thickness is decreased to about 6-7 nm, defects are either no longer present, or, more likely, are incapable of trapping charge at room temperature because trapped carriers can either tunnel to one of the interfaces, or be annihilated by a reverse process. It appears possible also that the precursor of the several types of defects only forms at a “grown” silicon-silicon oxide interface. In theory, this would make it possible to grow defect free insulators by a combination of deposition and oxidation processes.     

Method for three-dimensional data registration from disparate imaging modalities in the NOGA Myocardial Viability Trial

Region-by-region comparison of data concerning left ventricular (LV) status is difficult to perform quantitatively if the data was acquired from disparate imaging modalities. We validated a method for comparing measurements obtained by electromechanical mapping (EMM) catheter with dobutamine stress echocardiography (DSE) via biplane contrast ventriculography, with the assistance of three-dimensional (3-D) echocardiographic data. The ventriculograms were traced and the borders were used to reconstruct the LV in 3-D with the aid of a database of 3-D echocardiographic studies. The 3-D LV was oriented to the EMM data based on the body coordinates and then manually scaled and translated to fit. The EMM data were mapped to the 3-D surface. The 3-D surface was divided into the 16 regions defined for echocardiographic assessment. The mean EMM value for local linear shortening, a parameter of function, was computed in each segment. The EMM and semiquantitative echocardiographic assessments of regional myocardial function were compared by segment, and the volume of the 3-D LV was compared with the volume computed from the ventriculogram. The volume of the 3-D surface correlated closely with that of the ventriculogram (r = 0.97, SEE = 27.4 ml) but with a significant overestimation of 63 +/- 35 ml. There was a highly significant (p < 0.0001) agreement in regional function between EMM and echo. Local linear shortening correlated significantly (p < 0.0001) with echocardiographic severity of wall motion, averaging 9.5 +/- 6.5, 8.1 +/- 5.4, 5.9 +/- 4.8, and 6.2 +/- 3.3 in segments read as normal, hypokinetic, akinetic, and dyskinetic, respectively. The method presented is valid for comparing cardiac parameters derived from disparate image data on a region-by-region basis by employing anatomic landmarks on 3-D reconstructions of the LV endocardial surface.