Extended Defects In Semiconductors Research Articles

Nanoscale Infrared Spectroscopic Characterization of Extended Defects in 4H-Silicon Carbide.

Extended defects in wide-bandgap semiconductors have been widely investigated using techniques providing either spectroscopic or microscopic information. Nano-Fourier transform infrared spectroscopy (nano-FTIR) is a nondestructive characterization method combining FTIR with nanoscale spatial resolution (∼20 nm) and topographic information. Here, we demonstrate the capability of nano-FTIR for the characterization of extended defects in semiconductors by investigating an in-grown stacking fault (IGSF) present in a 4H-SiC epitaxial layer. We observe a local spectral shift of the mid-infrared near-field response, consistent with the identification of the defect stacking order as 3C-SiC (cubic) from comparative simulations based on the finite dipole model (FDM). This 3C-SiC IGSF contrasts with the more typical 8H-SiC IGSFs reported previously and is exemplary in showing that nanoscale spectroscopy with nano-FTIR can provide new insights into the properties of extended defects, the understanding of which is crucial for mitigating deleterious effects of such defects in alternative semiconductor materials and devices.

19th International Conference on Extended Defects in Semiconductors (EDS2018)

FOREWORDThis Proceedings is a collection of peer-reviewed papers presented at EDS2018, a biannual International Conference on “Extended Defects in Semiconductors”, which was held June 24-29, 2018 in Thessaloniki, Greece. Nineteenth in the series of EDS conferences, the scope of EDS2018 was twofold: to assess the current state of knowledge on the properties of heterophase interfaces in the presence of defects and to consider the impact of this knowledge on low-dimension nanostructures and on the design of devices influencing their electronic, opto-electronic, magnetic, and mechanical properties.The conference covered new results with emphasis placed on research addressing the role of extended defects on limiting device performance, new developments in methodologies and tools for defect engineering in semiconducting materials, and advanced characterization techniques. Invited lectures dealing with materials science fundamentals and methodology added educational content especially directed to doctoral and post-doctoral students.It is hoped that this Proceedings provide the reader with a timely standpoint on the fast-evolving subject of Extended Defects in Semiconductors.List of Organisation and Conference Photo are available in this PDF.

Extended Defects in Semiconductors

AbstractThis proceedings volume of physica status solidi contains papers presented at the 17th International Conference on Extended Defects in Semiconductors (EDS 2014). They have been selected during a peer‐review process.The conference was organized by the Georg‐August‐University Göttingen and was held at the Physics Faculty as part of the university's North Campus in Göttingen from September 14 to 19, 2014. The biennial conference series on Extended Defects in Semiconductors started with a meeting in Hünfeld, Germany, in 1978. Subsequent meetings took place in France, Great Britain, Germany, Italy, Poland, Russia and the preceding EDS 2012 in Thessaloniki (Greece).EDS 2014 was a conference following the tradition of previous conferences of this series, i.e. it brought together experts in fundamental and applied research on structural defects in current and future semiconducting material systems, their nanostructures and devices. For the first time, carbon‐related materials had been included. It provided a forum for excellent presentations and lively discussions in a stimulating scientific atmosphere.Topics of the conference included– Thin films and heterostructures– Low‐dimensional systems and related defects: semiconductor nanocrystals, quantum wells, quantum dots, nanowires– Extended defects in C‐related materials (incl. graphen)– Interface structures and defect interaction– Doping‐, irradiation‐, and implantation‐induced defects– Electronic structure of defects– Defect engineering, strain engineering– Mechanical properties and dislocation dynamics– Role of defects in optoelectronic and magnetic properties– Degradation mechanisms in semiconductor devices– Atomistic and multiscale simulations, modeling approaches of defects, interfaces and nanostructures– Advanced characterisation techniques and methods for the investigation of semiconductor materials, in‐situ imaging and analysis– Interaction of point and extended defects, point defect agglomeration– Materials for solar energy conversion and energy storage.The organizers want to express their gratitude to all members of the EDS Scientific Committee as well as to the members of the EDS 2014 Program Committee and all referees for their invaluable work. Support by the Georg‐August‐University and the CRC1073 is also gratefully acknowledged.Last but not least, we thank all participants of EDS 2014 whose excellent contributions built the base for a fruitful and stimulating conference. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Extended Defects in Semiconductors

AbstractThis Proceedings issue of physica status solidi contains papers presented as oral and poster contributions at the International Conference on Extended Defects in Semiconductors (EDS 2012). EDS 2012 belonged to the biennial Extended Defects in Semiconductors conference series that started in 1978 with a meeting in Hünfeld, Germany. Subsequent meetings took place in Poland, France, Great Britain, Germany, Russia, and Italy. EDS 2010 was held at the University of Sussex in Brighton, UK.EDS 2012 took place in Thessaloniki, Greece, on June 24‐29, 2012. It was organized by the Department of Physics of the Aristotle University of Thessaloniki.The aim of the conference was to target the overall vision of research activities of the scientific community, based on needs that stem from technological bottlenecks involving structural defects in present day and future polynanocrystalline and nanostructured semiconductor material systems and their role in the functionality of innovative nanodevices. Within this objective, invited talks and contributions provided a stimulating conference program covering the following topics:– Thin films and heterostructures– Low‐dimensional systems and related defects: semiconductor nanocrystals, quantum wells, quantum dots, nanowires– Interface structures and defect interactions– Doping/irradiation/implantation‐induced defects– Electronic structure of defects– Defect engineering, strain engineering– Mechanical properties and dislocation dynamics– Role of defects in opto‐electronic and magnetic properties– Degradation mechanisms in semiconductor devices– Atomistic and multiscale simulations, modeling approaches of defects, interfaces and nanostructures– Advanced characterization techniques and methods for the investigation of semiconductor materialsI would like to thank the members of the EDS 2012 International Advisory, Program and Organizing Committees, as well as the authors, referees, and guest editors, for their invaluable contributions towards the success of this conference and proceedings (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Helmut Alexander – A Life for Science – Alive in Science

Helmut Alexander was one of the four initiators of the "International Symposium on Dislocations in Tetrahedrally Coordinated Semiconductors" (Hünfeld 1978). This conference was the beginning of a conference series which got its new name EDS (Extended Defects in Semiconductors) first in 1980. He who gave his name to the "Helmut Alexander Award" of the EDS conference died on the third of December, 2009. The international advisory committee of EDS honoured his scientific work in 2002 recognizing him by instituting an award for the best poster presentation for a young scientist at the running conference session. The authors try to review his life with some of his scientific highlights.

Localization and preparation of recombination-active extended defects for transmission electron microscopy analysis

Recombination-active extended defects in semiconductors frequently occur at a low density which makes their structural and chemical analysis by transmission electron microscopy (TEM) techniques virtually impossible. Here an approach is described that uses in situ electron beam induced current (EBIC) in a focused ion beam machine to localize such defects for TEM lamella preparation. As an example, a defect complex occurring in block-cast multicrystalline silicon with a density of less than 10(4) cm(-3) has been prepared and analyzed by TEM. The chemical sensitivity of the technique is estimated to be about 10(13) atoms cm(-2) which is comparable to synchrotron-based x-ray techniques. The localization accuracy of the TEM lamella is shown to be better than 50 nm when low-energy EBIC is used.

Ab initio based multiscale modelling for materials science

Materials modelling of extended defects in semiconductors (and many other systems) requires both detailed electronic models of matter to account for bond breaking and formation at the atomic scale and the representation of material systems at large scales, in the micrometre–microsecond range. These twin demands, if implemented directly by ab initio calculations, are unachievable with potentially available computational resources for the foreseeable future. An alternative approach is to develop multiscale simulations, where the level of simulation detail can vary in time and space, thus saving on computational cost without sacrificing the necessary detailed modelling. This paper introduces the basic concepts and reviews some progress in this field, and the related challenges along two main strands: (i) sequential multiscale modelling to construct larger-scale material models from first principles and (ii) hybrid multiscale modelling for the description of unitary systems which are too large for monoscale modelling at the desired accuracy.

Preface: Phys. Status Solidi C 6/8

AbstractThis proceedings issue of physica status solidi contains papers presented as oral and poster contributions at the International Conference on Extended Defects in Semiconductors (EDS 2008). This conference was held in France at the new campus of Poitiers University situated in the Futuroscope area on 14–19 September 2008 and was organized by PHYMAT laboratory (UMR 6630 of CNRS and University of Poitiers). The EDS conference series was inaugurated in Hünfeld (Germany) and was followed by conferences in Poland, France, Great Britain, Germany, and Russia. The EDS 2008 is the direct follower of the conferences of 2004 held in Chernogolovka (Russia) and 2006 in Halle (Germany).The aim of the conference was to provide a forum on the current state‐of‐the‐art of investigation and modelling of extended defects in semiconductors in order to achieve a deeper understanding of lattice imperfections, their interaction, and their role in the development of semiconductor technology. The following main topics were covered:– Relation between extended defects and nanostructures in semiconductors– Defect structure: defect imaging and modelling– Electronic structure of extended defects– Mechanical properties and dislocations: nucleation and dynamics– Interaction between defects– Structure of strained layers– Defects in thin films and interfaces, interface structures– Role of extended defects in devices, defects engineering– Narrow and wide band gap materials– Defects in solar cell materials and photovoltaic devices– Embedded semiconductor nanoparticles, quantum dot like “extended defects”– Implantation‐induced extended defectsAs a new approach, we emphasized semiconductor behaviour under severe environment (high temperature, complex and high stress field and irradiation). Indeed, both experimental and modelling approaches of extended defect nucleation and properties deserve challenging understanding under these harsh conditions, in which important applications are expected for semiconductors.We wish to thank the members of the EDS 2008 Scientific and Organizing Committees, the sponsors, as well as the referees and authors who made this conference and proceedings a success. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Information for authors: Phys. Status Solidi C 6/8

physica status solidi cVolume 6, Issue 8 p. 1990-1991 Information for authors Information for authors: Phys. Status Solidi C 6/8 First published: 10 August 2009 https://doi.org/10.1002/pssc.200960068AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume6, Issue8Special Issue: International Conference on Extended Defects in Semiconductors (EDS 2008)August 2009Pages 1990-1991 RelatedInformation

Preface: phys. stat. sol. (c) 4/8

AbstractThis issue of physica status solidi – Proceedings contains papers presented as oral and poster contribu‐tions at the International Conference on Extended Defects in Semiconductors (EDS 2006) held in Halle, Germany, on 17–22 September 2006. The event was organized by the Martin‐Luther‐Universität Halle–Wittenberg, the Max‐Planck‐Institut für Mikrostrukturphysik Halle, and the Fraunhofer‐Institut für Werkstoffmechanik Halle. The EDS conference series was inaugurated in Hünfeld (Germany) and followed by conferences in Poland, France, Great Britain, Germany, and Russia. The EDS 2006 is the direct follower of the conferences of 2002 held in Bologna (Italy) and 2004 in Chernogolovka (Russia). Although there were some difficulties in numbering the EDS conferences, we followed the scheme in‐troduced at the conference in Brighton 2000 and define our meeting as EDS13. In order to appreciate the 1200th anniversary of the city of Halle in 2006, we selected the famous five towers of the market square as the conference logo. The dislocation expert, however, will recognize a dislocation line, pinned by glide obstacles.The aim of the conference was to provide a forum on the current state of art of investigation and modeling of extended defects in semiconductors in order to achieve a deeper understanding of lattice imperfections, their interaction, and their role in the development of semiconductor technology. The following main topics were covered: Structure of defects, defect imaging, structure modelling, electronic structure of extended defects, mechanical properties and dislocation dynamics, interaction between different kinds of defects, structure of strained layers, compliant substrates, wafer bonding, defects in thin films and interfaces, interface structures, role of extended defects in devices, utilizing of defects for devices, wide band gap materials (SiC, diamond, ZnO, III–V nitrides), defects in solar cell materials and photovoltaic devices, embedded semiconductor nanoparticles, and quantum‐dot‐like “extended defects”.As a new topic, we introduced a crossover between extended defects and nanostructures in semiconductors. We think that the comparison of experiments and the theoretical description of extended defects and nanostructures in semiconductors may give exciting new insights into the understanding of dimensionally confined systems in general. This approach will certainly be extended in the next EDS conference to be held in Poitiers, France, in 2008.We dedicate this proceedings volume to our friend and colleague Jürgen Schreiber, who suddenly passed away during the preparation of this conference. His cathodoluminescence studies on dislocations in semiconductors will be a lasting contribution to the defect community.Halle, January 2007

Defects in silicon plastically deformed at room temperature

The article [1] describes specific features of positron trapping in silicon plastically deformed at room temperature. The results are related to the dislocation core structure and the inhomogeneous deformation. The picture shows the probability density function of a positron localized in a vacancy in silicon. The calculation was performed with the superimposed-atom model. The degree of localization and consequently the defect-related positron lifetime vary for different open-volume defects, such as vacancies, voids, and dislocations. The first author, Hartmut S. Leipner, is CEO of the Center of Materials Science of the University Halle–Wittenberg. His research activities are focused on the characterization of extended defects in semiconductors.

Segregation of dopant atoms on extended defects in semiconductors

We performed a theoretical investigation on the interaction of dopant atoms with extended defects in semiconductors using ab initio total energy calculations. Dopant atoms (donors and acceptors) were found to segregate in stacking faults in silicon and in gallium arsenide, with segregation energies as large as 0.2 eV. A general trend on the electronic properties of segregated dopants in stacking faults is that the donor (or acceptor) electronic energy levels become deeper in the electronic gap, as compared to those levels for the defect in a crystalline site.

Makyoh Topography for the Study of Large-Area Extended Defects in Semiconductors

A quantitative approach to the Makyoh-topography image formation mechanism is presented. General relations are given on the optical settings; geometrical optical simulations of a sinusoidal surface and a hillock (or depression) are presented. Optimum working conditions are established, and general features of the imaging are pointed out. The experimental images taken for Si wafers are compared to the results of the model.

Deep-Level Transient-Spectroscopy for Localized States at Extended Defects in Semiconductors

We prove that for localized states at extended defects the high-temperature sides of deep-level transient spectra can be written as a product of an amplitude function depending on the pulse length and a shape function depending on temperature. By this property localized states can be distinguished experimentally from bandlike states. Simulations of deep level transient spectra for localized and bandlike states using the same density of states function and parameter values illustrate the differences and show the failures of conventional analysis in both cases.

Effect of hydrogenation on the properties of extended defects in semiconductors

Hydrogen is introduced in semiconductors in order to improve their electronic properties. It can also be present in many cases as a result of material preparation. We first briefly review the various means and mechanisms of introduction of hydrogen, and its influence on the shallow levels. Assessment of the electrical properties of extended defects is reviewed, with a special emphasis on the beam injection techniques. It is shown how hydrogenation can passivate the electrical activity of deep levels associated to grain boundaries, dislocations, surfaces or interfaces, in crystalline semiconductors. The issues of the thermal stability of the hydrogen in the samples as well as that of the prevention against surface damage during hydrogen treatments are discussed.

Bandlike and localized states at extended defects in silicon.

We show that electronic states at extended defects in semiconductors can be classified as bandlike or localized using deep-level transient spectroscopy (DLTS), when electron equilibration at the defect is taken into account. We compare computer simulations of DLTS with data for 60\ifmmode^\circ\else\textdegree\fi{} dislocations and for ${\mathrm{NiSi}}_{2}$ platelets in silicon and find narrow point defect clouds in the first and a two-dimensional metal or a metal ring in the second example.

Apparatus for digital electron-beam-induced current imaging

Abstract A new electron-beam-induced current (EBIC) apparatus for studying charge carrier recombination at extended defects in semiconductors is described. It employs computer-automated measurement and control equipment to acquire high resolution beam-induced current images using a conventional scanning electron microscope. The EBIC images typically contain a matrix of 512 × 512 digitally measured points, each points, which is a result of multiple averaging. The images can be displayed on a workstation monitor and image processing using commercially available software packages can be performed. All the components of the system and software, except the data acquisition software routines, are readily available as off-the-shelf items. A method of calibrating the equipment in terms of quantum efficiency by scanning well-characterized solar cells of known material and physical properties was developed. As an example of an application, a modified quantitative analysis method is applied to the problem of precipitates that act as point recombination centers distributed through a Czochralski silicon solar cell. The analysis, based on non-linear curve fitting, results in a characterization of the strength of the charge carrier recombination at a given defect and the depth of the defect below the sample surface.

Digital electron beam induced current imaging: Apparatus and analysis

The electron beam induced current (EBIC) method is a well known technique for studying charge carrier recombination at extended defects in semiconductors. In this work a new electron beam induced current apparatus is described. It employs computer automated measurement and control equipment to acquire high resolution beam induced current images using a conventional secondary electron microscope. The electron beam induced current images typically contain a matrix of 512×512 digitally measured points. They can be displayed on a workstation monitor and imaging processing can be performed. The increased current resolution of the apparatus necessitated the modification of traditional quantitative EBIC analysis methods. The modified quantitative analysis method is presented and applied to the problem of precipitates contained in a Czochralski silicon solar cell. It results in a characterization of the amount of charge carrier recombination at the defects and a calculation of the depth of the defects below the sample surface.

A Fourier-transform spectrometer for infra-red cathodoluminescence in TEM

The study of the electronic structure of deep states associated with isolated, well characterised extended defects in semiconductors requires the use of a cathodoluminescence apparatus for TEM in the wavelength range 1-50 microns (1.2 - 0.02 eV). This would also allow the study of the III-V alloys and their defects used for I.R. emitters and lasers. Preliminary results using a grating spectrometer have been obtained by Petroff, however experience from Astronomy indicates that the Fellgett + Jacquinot advantage obtainable using Fourier Transform Infrared Spectroscopy (F.T.I.R.S.) is important for weak sources and noisy detectors. (See Davidson who has compared both techniques in SEM).The crucial design problem in the 1-10 micron range is the mirror movement in the Michelson Interferometer, which must be reproduceably positioned with submicron accuracy over a one centimeter range.