VLSI Revisited - Revival in Japan

This paper describes the abundance of semiconductor consortia that have come into existence in Japan since the mid-1990s. They clearly reflect the ambition of the government - through its reorganized ministry METI and company initiatives - to regain some of the industrial and technological leadership that Japan has lost. The consortia landscape is very different in Japan compared with EU and the US. Outside Japan the universities play a much bigger and very important role. In Europe there has emerged close collaboration, among national government agencies, companies and the EU Commission in supporting the IT sector with considerable attention to semiconductor technologies. Another major difference, and possibly the most important one, is the fact that US and EU consortia include and mix partners from different areas of the semiconductor landscape including wafer makers, material suppliers, equipment producers and integrated device makers.semiconductors, Hitachi, Sony, Toshiba, Elpida, Renesas, Sematech, VLSI, JESSI, MEDEA, ASPLA, MIRAI, innovation system

VLSI REVISITED – REVIVAL IN JAPAN

This paper describes the abundance of semiconductor consortia that have come into existence in Japan since the mid-1990s. They clearly reflect the ambition of the government – through its reorganized ministry METI and company initiatives - to regain some of the industrial and technological leadership that Japan has lost. The consortia landscape is very different in Japan compared with EU and the US. Outside Japan the universities play a much bigger and very important role. In Europe there has emerged close collaboration, among national government agencies, companies and the EU Commission in supporting the IT sector with considerable attention to semiconductor technologies. Another major difference, and possibly the most important one, is the fact that US and EU consortia include and mix partners from different areas of the semiconductor landscape including wafer makers, material suppliers, equipment producers and integrated device makers.semiconductors; Hitachi; Sony; Toshiba; Elpida; Renesas; Sematech; VLSI; JESSI; MEDEA; ASPLA; MIRAI; innovation system

Applied Nanofabrication for X-ray Grating Spectroscopy

Measuring the diffuse, highly-ionized baryonic content in galactic halos and the intergalactic medium through soft x-ray absorption spectroscopy of active galactic nuclei is a main scientific objective of the Lynx X-ray Observatory mission concept that can only be accomplished with a next-generation grating spectrometer. Realizing such an instrument using reflection grating technology requires thousands of custom blazed gratings that each perform with high diffraction efficiency to be manufactured and aligned to intercept radiation coming to a focus in a Wolter-I telescope. The aim of this thesis is to implement two recently-developed techniques in nanofabrication for this task, with an emphasis on beamline diffraction-efficiency testing for characterizing spectral sensitivity. In particular, thermally-activated selective topography equilibration (TASTE) is pursued as a means for fabricating a master grating with the key advantage that it enables blazed groove facets to be patterned in polymeric electron-beam resist over a non-parallel groove layout not limited by substrate crystal structure. Additionally, substrate-conformal imprint lithography (SCIL) is studied as a method for mass manufacturing high-fidelity grating replicas in a silica sol-gel resist while avoiding many of the detriments associated with large-area patterning in other nanoimprint techniques. Diffraction-efficiency testing of sub-micron grating prototypes coated with gold shows that TASTE is capable of meeting Lynx requirements for spectral sensitivity, with room for improvement at small groove periods, and that while SCIL offers a promising avenue for Lynx grating production, imprints suffer a small blaze-angle reduction due to resist shrinkage. Accompanying this dissertation are appendices that outline physics fundamentals for x-ray spectral lines, x-ray optics, and diffraction gratings.Comment: Ph.D. thesis in Astronomy & Astrophysics (373 total pages; 171 pages of chapters & 141 pages of appendices with 113 figures & 19 tables), The Pennsylvania State University, Advisor: Randall L. McEntaffer. Defended 12/18/2020. URL: https://etda.libraries.psu.edu/catalog/18627jam111

Earth Abundant Thin Film Technology for Next Generation Photovoltaic Modules

With a cumulative generation capacity of over 100 GW, Photovoltaics (PV) technology is uniquely poised to become increasingly popular in the coming decades. Although, several breakthroughs have propelled PV technology, it accounts for only less than 1% of the energy produced worldwide. This aspect of the PV technology is primarily due to the somewhat high cost per watt, which is dependent on the efficiency of the PV cells as well as the cost of manufacturing and installing them. Currently, the efficiency of the PV conversion process is limited to about 25% for commercial terrestrial cells; improving this efficiency can increase the penetration of PV worldwide rapidly. A critical review of all possibilities pursued in the public domain reveals serious shortcomings and manufacturing issues. To make PV generated power a reality in every home, a Multi-Junction Multi-Terminal (MJMT) PV architecture can be employed combining silicon and another earth abundant material. However, forming electronic grade thin films of earth abundant materials is a non-trivial challenge; without solving this, it is impossible to increase the overall PV efficiency. Deposition of Copper (I) Oxide, an earth abundant semiconducting material, was conducted using an optimized Photo assisted Chemical Vapor Deposition process. X-Ray Diffraction, Ellipsometry, Transmission Electron Microscopy, and Profilometry revealed that the films composed of Cu2O of about 90 nm thickness and the grain size was as large as 600 nm. This result shows an improvement in material properties over previously grown thin films of Cu2O. Measurement of I-V characteristics of a diode structure composed of the Cu2O indicates an increase in On/Off ratio to 17,000 from the previous best value of 800. These results suggest that the electronic quality of the thin films deposited using our optimized process to be better than the results reported elsewhere. Using this optimized thin film forming technique, it is now possible to create a complete MJMT structure to improve the terrestrial commercial PV efficiency

Nanoantennas for visible and infrared radiation

Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-ofstates engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of optical antennas based on the background of both well-developed radiowave antenna engineering and the emerging field of plasmonics. In particular, we address the plasmonic behavior that emerges due to the very high optical frequencies involved and the limitations in the choice of antenna materials and geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.Comment: Review article with 76 pages, 21 figure

Phase Shaping In The Infrared By Planar Quasi-periodic Surfaces Comprised Of Sub-wavelength Elements

Reflectarrays are passive quasi-periodic sub-wavelength antenna arrays designed for discrete reflected phase manipulation at each individual antenna element making up the array. By spatially varying the phase response of the antenna array, reflectarrays allow a planar surface to impress a non-planar phasefront upon re-radiation. Such devices have become commonplace at radio frequencies. In this dissertation, they are demonstrated in the infrared for the first time--at frequencies as high as 194 THz. Relevant aspects of computational electromagnetic modeling are explored, to yield design procedures optimized for these high frequencies. Modeling is also utilized to demonstrate the phase response of a generalized metallic patch resonator in terms of its dependence on element dimensions, surrounding materials, angle of incidence, and frequency. The impact of realistic dispersion of the real and imaginary parts of the metallic permittivity on the magnitude and bandwidth of the resonance behavior is thoroughly investigated. Several single-phase reflectarrays are fabricated and measurement techniques are developed for evaluating these surfaces. In all of these cases, there is excellent agreement between the computational model results and the measured device characteristics. With accurate modeling and measurement, it is possible to proceed to explore some specific device architectures appropriate for focusing reflectarrays, including binary-phase and phase-incremental approaches. Image quality aspects of these focusing reflectarrays are considered from geometrical and chromatic-aberration perspectives. The dissertation concludes by briefly considering two additional analogous devices--the transmitarray for tailoring transmissive phase response, and the emitarray for angular control of thermally emitted radiation

NEMS/MEMSによる次世代有機ELシステム技術に関する研究

早大学位記番号:新7978早稲田大

AI/ML Algorithms and Applications in VLSI Design and Technology

An evident challenge ahead for the integrated circuit (IC) industry in the nanometer regime is the investigation and development of methods that can reduce the design complexity ensuing from growing process variations and curtail the turnaround time of chip manufacturing. Conventional methodologies employed for such tasks are largely manual; thus, time-consuming and resource-intensive. In contrast, the unique learning strategies of artificial intelligence (AI) provide numerous exciting automated approaches for handling complex and data-intensive tasks in very-large-scale integration (VLSI) design and testing. Employing AI and machine learning (ML) algorithms in VLSI design and manufacturing reduces the time and effort for understanding and processing the data within and across different abstraction levels via automated learning algorithms. It, in turn, improves the IC yield and reduces the manufacturing turnaround time. This paper thoroughly reviews the AI/ML automated approaches introduced in the past towards VLSI design and manufacturing. Moreover, we discuss the scope of AI/ML applications in the future at various abstraction levels to revolutionize the field of VLSI design, aiming for high-speed, highly intelligent, and efficient implementations