No abstract

No abstract

Postmodernism -Culture as a SignIf you asked me "What is postmodernism?" I would be hard put for an answer. We are, of course, wont to expect that the suffix ism circumscribes either a Weltanschauung or a position or an argument. When Jean Baudrillard blots out the difference between illusion and reality by declaring culture a "limitless proliferation of signs" (Baudrillard 1988, p. 22), I take it to be an imaginative and seductive instance of Weltanschauung. When Jacques Derrida makes "writing" his point of view, I consider it a philosophical position. When Paul de Man criticizes the rhetoric of romanticism, I judge it as a literary argument. But postmodernism is all this and many more things, so the answer is still very much in the open. What these authors have in common is the rhetorical point of view, which says that reason is determined, not by logic, but by the turns and twists of metaphoric language. We may believe ourselves to be the masters and users of language. In fact it is more apt to say that language masters us. Language can then be described as a system of signs which is itself the repository of meaning, independent of reference to the "facts" of the world or the intentions of a subject.Instead of being defined by the correspondence between word and world or between sign and its factual referent, meaning is now found in the relation between signs. That is to say, signs do not have meaning in themselves but get their meaning by the distinctive place they occupy in contrast to other signs in the network of language. This, incidentally, makes the traditional search for definitions not only dubious, but futile. A definition fixes the relation between signifier and signified, between word and concept. The postmodernist wants, by contrast, to untie that connection to allow the free play of signs. He doesn't seek identity but the multiple and equivocal. Now, why not go along with postmodernism and give up trying to define it. We may still use postmodernism as an index term pointing towards a different position, a position that even makes difference itself its point of view. We may talk about postmodernity as the manifold and many-faceted differentiations of the (post) modern world. This document is copyrighted by the American Psychological Association or one of its allied publishers.This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.

Electrically active, unintentionally introduced defects in a semiconductor crystal may lead to undesirable device properties, and it is therefore important to gain control and understanding of such defects in order to achieve control at device level. Intrinsic defects are usually harder to remove and control than impurities, and in SiC these defects are not only numerous, but also extremely thermally stable, making them somewhat difficult to remove or deactivate. Bulk defects, specifically those corresponding to the Z 1/2 and EH 6/7 levels measured using deep level transient spectroscopy (DLTS), appear in concentrations around 10 12-10 13 cm −3 in as-grown material, while the density of interface states (D it) numbers around 10 14 eV −1 cm −2 in typical thermally oxidized 4H-SiC material. These two factors severely limit the minority carrier lifetime and the channel mobility in MOS-devices, respectively, and are therefore highly relevant problems to study and-if possible-solve.

PACS number(s): 71.55.−i, 99.10.Cd There are three errors in the numbering of references in this manuscript. On page 4, right column, first paragraph, Ref. 30 should be Ref. 33 (Song et al.). On page 6, left column, second paragraph, Ref. 33 should be Ref. 36 (Bockstedte et al.) and the same applies to the last reference in this paragraph. This does not affect the conclusions of the manuscript, nor any other aspect of the work.

Density of interface states, electron traps, and hole traps as a function of the nitrogen density in SiO 2 on SiCInterfaces between 4H-SiC and Si O 2 : Microstructure, nanochemistry, and near-interface traps J. Appl. Phys. 97, 034302 (2005); 10.1063/1.1836004 Study on electron trapping and interface states of various gate dielectric materials in 4H-SiC metal-oxidesemiconductor capacitors Electron states at the SiO 2 / 4H -SiC interface have been investigated using capacitor structures and especially, the influence of excess nitrogen, introduced by ion implantation, at the interface is studied in detail. Implanted and nonimplanted n-type samples with an interfacial concentration of nitrogen of ϳ10 19 cm −3 and 10 16 cm −3 , respectively, were analyzed by capacitance-voltage ͑C-V͒ measurements, performed at different temperatures and probe frequencies, and thermal dielectric relaxation current ͑TDRC͒ measurements performed in the temperature range of 35-295 K. Three main categories of electron states are disclosed, true interface states ͑D it ͒, fast near interface states ͑NIT ox fast ͒ and slow near interface states ͑NIT ox slow ͒. The density versus energy distributions of D it and NIT ox fast have been deduced from the TDRC data and they are shown to give a close quantitative agreement with the shape and frequency dependence of the C-V curves. Further, the amount of NIT ox slow extracted from TDRC is demonstrated to be responsible for the parallel shifts and hysterezis effects occurring in the C-V characteristics. All three categories of electron states are reduced in concentration in the implanted samples. This holds particularly for NIT ox fast with a peak at ϳ0.1 eV below the conduction band edge of 4H-SiC that is suppressed by at least two orders of magnitude relative to the nonimplanted samples. The decrease for D it is also substantial ͑a factor of ϳ10͒ while the loss for NIT ox slow is considerably smaller ͑only ϳ30%͒. The results provide firm evidence that NIT ox fast and NIT ox slow do not originate from the same kind of defect center.

High-purity epitaxial layers of n-type 4H-SiC have been implanted with 4.3-MeV Si ions to a dose of 3 × 10 8 cm −2 and then subjected to dry isothermal oxidation at temperatures between 1050 and 1175 • C. Analysis of the samples by depth-resolved deep level transient spectroscopy unveils a strong oxidation-enhanced annealing of the prominent Z 1/2 center, commonly ascribed to the carbon vacancy. The integrated (total) loss of Z 1/2 centers is proportional to the thickness of the silicon dioxide (SiO 2) layer grown but the proportionality constant, or annihilation efficiency, decreases with decreasing oxidation temperature. At a given depth x, the annealing of Z 1/2 obeys first-order kinetics with a rate constant c having an activation energy of ∼5.3 eV. The pre-exponential factor c decreases with increasing x and a normalized concentration-versus-depth distribution of the species injected from the surface and annihilating the Z 1/2 centers has been deducted. This species is believed to be the carbon interstitial and is labeled C I : numerical simulations of the reaction kinetics employing a model where (i) the generation rate of C I at the SiO 2 /SiC interface is related to the oxidation rate, (ii) the diffusion of C I into the SiC layer is fast, and (iii) a steady-state concentration profile of C I is rapidly established, yield good agreement with the experimental data for the evolution of both Z 1/2 (absolute values) and C I (relative values) with temperature, depth, and time. The activation energy obtained for the diffusivity of C I is ∼3.0 eV, presumably reflecting the migration barrier for C I and possibly some contribution from an extra barrier to be surmounted at the SiO 2 /SiC interface.

In this article, I propose a link, or at least a family likeness, between two great traditions, Dewey's pragmatism and continental phenomenology and hermeneutics, held together by an overlapping epistemological and ethical outlook. My argument is based on a tripod of terms: situation, experience, and reconstruction. I start by describing 'situation' as the a priori condition for having experiences: there simply has to be a situation for sensing, thinking, and making decisions to take place. My next point is that experiences are necessarily place bound, local, and everyday phenomena. Experiences are relational in the sense of a subject who relates to the (material) world and to significant others*the subject not as an isolated ego, but as being-withthe-other. The link between experience and reconstruction may not be so obvious to us. But it is Dewey more than anybody else who has made a case for democracy as a political reconstruction of our everyday experiences. There is a connection between his epistemological and ethical outlook, and political action as part of an education for a democratic life.