Performance analysis of fault-tolerant nanoelectronic memories

Performance growth in microelectronics, as described by Moore’s law, is steadily approaching its limits. Nanoscale technologies are increasingly being explored as a practical solution to sustaining and possibly surpassing current performance trends of microelectronics. This work presents an in-depth analysis of the impact on performance, of incorporating reliability schemes into the architecture of a crossbar molecular switch nanomemory and demultiplexer. Nanoelectronics are currently in their early stages, and so fabrication and design methodologies are still in the process of being studied and developed. The building blocks of nanotechnology are fabricated using bottom-up processes, which leave them highly susceptible to defects. Hence, it is very important that defect and fault-tolerant schemes be incorporated into the design of nanotechnology related devices. In this dissertation, we focus on the study of a novel and promising class of computer chip memories called crossbar molecular switch memories and their demultiplexer addressing units. A major part of this work was the design of a defect and fault tolerance scheme we called the Multi-Switch Junction (MSJ) scheme. The MSJ scheme takes advantage of the regular array geometry of the crossbar nanomemory to create multiple switches in the fabric of the crossbar nanomemory for the storage of a single bit. Implementing defect and fault tolerant schemes come at a performance cost to the crossbar nanomemory; the challenge becomes achieving a balance between device reliability and performance. We have studied the reliability induced performance penalties as they relate to the time (delay) it takes to access a bit, and the amount of power dissipated by the process. Also, MSJ was compared to the banking and error correction coding fault tolerant schemes. Studies were also conducted to ascertain the potential benefits of integrating our MSJ scheme with the banking scheme. Trade-off analysis between access time delay, power dissipation and reliability is outlined and presented in this work. Results show the MSJ scheme increases the reliability of the crossbar nanomemory and demultiplexer. Simulation results also indicated that MSJ works very well for smaller nanomemory array sizes, with reliabilities of 100% for molecular switch failure rates in the 10% or less range

Roadmap on quantum nanotechnologies

Quantum phenomena are typically observable at length and time scales smaller than those of our everyday experience, often involving individual particles or excitations. The past few decades have seen a revolution in the ability to structure matter at the nanoscale, and experiments at the single particle level have become commonplace. This has opened wide new avenues for exploring and harnessing quantum mechanical effects in condensed matter. These quantum phenomena, in turn, have the potential to revolutionize the way we communicate, compute and probe the nanoscale world. Here, we review developments in key areas of quantum research in light of the nanotechnologies that enable them, with a view to what the future holds. Materials and devices with nanoscale features are used for quantum metrology and sensing, as building blocks for quantum computing, and as sources and detectors for quantum communication. They enable explorations of quantum behaviour and unconventional states in nano- and opto-mechanical systems, low-dimensional systems, molecular devices, nano-plasmonics, quantum electrodynamics, scanning tunnelling microscopy, and more. This rapidly expanding intersection of nanotechnology and quantum science/technology is mutually beneficial to both fields, laying claim to some of the most exciting scientific leaps of the last decade, with more on the horizon

Silicon Nanodevices

This book is a collection of scientific articles which brings research in Si nanodevices, device processing, and materials. The content is oriented to optoelectronics with a core in electronics and photonics. The issue of current technology developments in the nanodevices towards 3D integration and an emerging of the electronics and photonics as an ultimate goal in nanotechnology in the future is presented. The book contains a few review articles to update the knowledge in Si-based devices and followed by processing of advanced nano-scale transistors. Furthermore, material growth and manufacturing of several types of devices are presented. The subjects are carefully chosen to critically cover the scientific issues for scientists and doctoral students

Determination of key device parameters for short- and long-channel Schottky-type carbon nanotube field-effect transistors

The Schottky barrier, contact resistance and carrier mobility in carbon nanotube (CNT) field-effect transistors (FETs) are discussed in detail in this thesis. Novel extraction methods and definitions are proposed for these parameters. A technology comparison with other emerging transistor technologies and a performance projection study are also presented. A Schottky barrier height extraction method for CNTFETs considering one-dimensional (1D) conditions is developed. The methodology is applied to simulation and experimental data of CNTFETs feasible for manufacturing. Y-function-based methods (YFMs) have been applied to simulation and experimental data in order to extract a contact resistance for CNTFETs. Both extraction methods are more efficient and accurate than other conventional approaches. Practical mobility expressions are derived for CNTFETs covering the ballistic as well as the non-ballistic transport regime which enable a straightforward evaluation of the transport in CNTs. They have been applied to simulation and experimental data of devices with different channel lengths and Schottky barrier heights. A comparison of fabricated emerging transistors based on similar criteria for various application scenarios reveals CNTFETs as promising candidates to compete with Si-based technologies in low-power static and dynamic applications. A performance projection study is suggested for specific applications in terms of the studied design parameters

21st Century Nanostructured Materials

Nanostructured materials (NMs) are attracting interest as low-dimensional materials in the high-tech era of the 21st century. Recently, nanomaterials have experienced breakthroughs in synthesis and industrial and biomedical applications. This book presents recent achievements related to NMs such as graphene, carbon nanotubes, plasmonic materials, metal nanowires, metal oxides, nanoparticles, metamaterials, nanofibers, and nanocomposites, along with their physical and chemical aspects. Additionally, the book discusses the potential uses of these nanomaterials in photodetectors, transistors, quantum technology, chemical sensors, energy storage, silk fibroin, composites, drug delivery, tissue engineering, and sustainable agriculture and environmental applications

FGQT Q04 - Standardization Roadmap on Quantum Technologies [written by the CEN-CENELEC Focus Group on Quantum Technologies (FGQT)]

In 2018, the European Commission launched its long term and large scale Quantum Technology FET Flagship Program. The European Commission is also very interested in boosting standards for quantum technologies (QT). The Quantum Flagship has its own cooperation and coordination activities to “coordinate national strategies and activities” and in its “Quantum Manifesto” [1] explicitly advises to form “advisory boards” to promote collaboration in standardization. The CEN/CENELEC Focus Group for Quantum Technologies (FGQT) was formed in June 2020 with the goal to support the plans of the Commission. Currently, a multitude of standardization activities in QT are ongoing worldwide. While there is overlap in certain areas, other areas of this wide technological field are not being addressed at all. A coordinated approach will be highly beneficial to unleash the full potential of standardization for speeding up progress—also because the pool of standardization experts available for quantum technologies is still very limited. Furthermore, not all areas are yet “ready for standardization”, i.e., while in some fields early standardization is capable of boosting progress, it may be a problem in other areas. Thus, an assessment of standardization readiness of the different areas is required, too. The FGQT was established to identify standardization needs and opportunities for the entire field of QT with the final goal to boost the establishment of new industries in Europe and consequently the development and engineering of unprecedented novel devices and infrastructures for the benefit of European citizens. The QT standardization roadmap follows a constructive approach, starting with basic enabling technologies, from which QT components and subsystems are constructed, which again are assembled into QT systems that in turn form composite systems, constituting the building blocks for use cases. Thus, the roadmap is structured approximating very closely the categories of the EC quantum technology FET Flagship Program: quantum communication, quantum computing and simulation, quantum metrology, sensing, and enhanced imaging, while the basic enabling technologies and sub-systems are organized in two pools —thus supporting re-use in the different system categories. The separate types of QT unit systems are then foundations of general QT infrastructures or composite systems. On the level of use cases, the QT standardization roadmap describes basic domains of applicability, so-called “meta use cases”, while the detailed use cases are listed in a separate document of the FGQT: “FGQT Q05 Use Cases”. Finally, the QT standardization roadmap presents an outlook and conclusions, including an actual prioritization of the single identified standardization needs in the form of sequence diagrams (Gantt charts). This approach differs slightly from the QT “Pillar design” of the EU Quantum Flagship but, in our opinion, it extends it and is better adapted to standardization purposes, while the former is optimally suited as a research program design. The FGQT is an open group of European-based experts, working in QT research areas or enabling technologies, and of developers of components, products, or services related to QT. If you are based in Europe, and interested in guidelines and standards to help setting up a research infrastructure, or structuring and boosting your market relevance; if you want to improve coordination with your stakeholders and are interested in coordination and exchange with other experts in the field of QT—please consider to join the CEN/CENELEC FGQT. NOTE 1 European QT standards development in CEN/CENELEC will take place in the new JTC 22 QT (Joint Technical Committee 22 on Quantum Technologies). The work in JTC 22 QT will be guided by the present roadmap doc ument, and it is expected that the FGQT roadmap-development activity will be absorbed/continued by JTC 22 Q

A Multicarrier Technique for Monte Carlo Simulation of Electrothermal Transport in Nanoelectronics

The field of microelectronics plays an important role in many areas of engineering and science, being ubiquitous in aerospace, industrial manufacturing, biotechnology, and many other fields. Today, many micro- and nanoscale electronic devices are integrated into one package. e capacity to simulate new devices accurately is critical to the engineering design process, as device engineers use simulations to predict performance characteristics and identify potential issues before fabrication. A problem of particular interest is the simulation of devices which exhibit exotic behaviors due to non-equilibrium thermodynamics and thermal effects such as self-heating. Frequently, it is desirable to predict the level of heat generation, the maximum temperature and its location, and the impact of these thermal effects on the current-voltage (IV) characteristic of a device. is problem is furthermore complicated by nanoscale device dimensions. As the ratio of surface area to volume increases, boundary effects tend to dominate the transfer of energy through a device. Effects such as quantum confinement begin to play a role for nanoscale devices as geometric feature sizes approach the wavelength of the particles involved. Classical approaches to charge transport and heat transfer simulation such as the drift-diffusion approach and Fourier’s law, respectively, do not provide accurate results at these length scales. Instead, the transport processes are governed by the semi-classical Boltzmann transport equation (BTE) with quantum corrections derived from the Schrodinger equation ̈ (SE). In this work, a technique is presented for coupling a 3D phonon Monte Carlo (MC) simulation to an electron multi-subband Monte Carlo (MSBMC) simulation. Both carrier species are first examined separately. An electron MC simulation of bulk silicon, a silicon n-i-n diode, and an intrinsic-channel fin-field effect transistor (FinFET) structure are also presented. A 3D phonon MC algorithm is demonstrated in bulk silicon, a silicon thin film, and a silicon nanoconstriction. These tests verify the correctness of the MC framework. Finally, a novel carrier scattering system which directly accounts for the interaction be- tween the two particle populations inside a nanoscale device is shown. e tool developed supports quantum size effects and is shown to be capable of modeling the exchange of energy between thermal and electronic particle systems in a silicon FinFET

Annual Report 2020 - Institute of Ion Beam Physics and Materials Research

As for everybody else also for the Institute of Ion Beam Physics and Materials Research (IIM), the COVID-19 pandemic overshadowed the usual scientific life in 2020. Starting in March, home office became the preferred working environment and the typical institute life was disrupted. After a little relaxation during summer and early fall, the situation became again more serious and in early December we had to severely restrict laboratory activities and the user operation of the Ion Beam Center (IBC). For the most part of 2020, user visits were impossible and the services delivered had to be performed hands-off. This led to a significant additional work load on the IBC staff. Thank you very much for your commitment during this difficult period. By now user operation has restarted, but we are still far from business as usual. Most lessons learnt deal with video conference systems, and everybody now has extensive experience in skype, teams, webex, zoom, or any other solution available. Conferences were cancelled, workshops postponed, and seminar or colloquia talks delivered online. Since experimental work was also impeded, maybe 2020 was a good year for writing publications and applying for external funding. In total, 204 articles have been published with an average impact factor of about 7.0, which both mark an all-time high for the Institute. 13 publications from last year are highlighted in this Annual Report to illustrate the wide scientific spectrum of our institute. In addition, 20 new projects funded by EU, DFG, BMWi/AiF and SAB with a total budget of about 5.7 M€ have started. Thank you very much for making this possible. Also, in 2020 there have been a few personalia to be reported. Prof. Dr. Sibylle Gemming has left the HZDR and accepted a professor position at TU Chemnitz. Congratulations! The hence vacant position as the head of department was taken over by PD Dr. Artur Erbe by Oct. 1st. Simultaneously, the department has been renamed to “Nanoelectronics”. Dr. Alina Deac has left the institute in order to dedicate herself to new opportunities at the Dresden High Magnetic Field Laboratory. Dr. Matthias Posselt went to retirement after 36 years at the institute. We thank Matthias for his engagement and wish him all the best for the upcoming period of his life. However, also new equipment has been setup and new laboratories founded. A new 100 kV accelerator is integrated into our low energy ion nanoengineering facility and complements our ion beam technology in the lower energy regime. This setup is particularly suited to perform ion implantation into 2D materials and medium energy ion scattering (MEIS). Finally, we would like to cordially thank all partners, friends, and organizations who supported our progress in 2020. First and foremost we thank the Executive Board of the Helmholtz-Zentrum Dresden-Rossendorf, the Minister of Science and Arts of the Free State of Saxony, and the Ministers of Education and Research, and of Economic Affairs and Energy of the Federal Government of Germany. Many partners from univer¬sities, industry and research institutes all around the world contributed essentially, and play a crucial role for the further development of the institute. Last but not least, the directors would like to thank all members of our institute for their efforts in these very special times and excellent contributions in 2020