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FUJITSU SCIENTIFIC & TECHNICAL JOURNAL (FSTJ)


FSTJ 2017-2 Cover Image

Current Issue: Devices and Materials for Human Centric Innovation

Vol. 53, No. 2, February 2017

The main business area of the Fujitsu Group has been changing from products to services. But, as a way to differentiate our services from those of competitors, device and materials technology is still important, as a basic technology that is also related to intellectual property and that can help us judge which new technologies we should use. This special issue introduces the leading-edge technologies of devices and materials that are the core of our technology value chain.

Japanese version: Magazine FUJITSU (Vol. 68, No. 1, January 2017)


Preface

Special issue on Devices and Materials for Human Centric Innovation (453 KB)
Ei Yano, Member of the Board, Fujitsu Laboratories Ltd., pp.1-2

Overview

Devices, Materials, and Packaging Technologies for Hyperconnected Cloud (826 KB)
Shigenori Aoki, pp.3-8
The progress of Hyperconnected Cloud (HyCC) sustaining the coming Internet of Things (IoT) era means that novel hardware technologies are needed for collecting data from the real world and for high-speed data processing with limited space and energy consumption. To collect novel data and enhance HyCC coverage, several kinds of compound semiconductor devices have been developed for wireless telecommunication equipment, millimeter-wave radars, and odor sensors. Advanced packaging technologies such as 3D device integration for minimal chip-to-chip distance and compact optical transceivers with maximum bandwidth are developed, for compact, high-speed, and cost-effective products. New materials breaking through the limitations of information and communications technology (ICT) are under development including nanocarbon, by combining a novel build-up synthesizing process with a materials informatics approach. This paper presents the devices, materials, and packaging technologies developed in Fujitsu Laboratories.

Material, Device, and Mounting Technologies to Support ICT Infrastructure

Compact Terahertz Receiver for Short-range Wireless Communications of Tens of Gbps (650 KB)
Yasuhiro Nakasha, Shoichi Shiba, Yoichi Kawano, Tsuyoshi Takahashi, pp.9-14
In the near future, trillions of things such as mobile smart devices, machine-to-machine (M2M) platforms, and sensors will be connected to networks and a huge amount of data will be flooded to cloud networks. A "hyper connected world" is dawning. Wireless communication systems that support this trend are required to be able to send a huge amount of data instantaneously. The transmission speed of the wireless communication systems has been increasing year by year and is anticipated to reach tens of Gbps and beyond. Radio signals with a frequency greater than 100 GHz are called terahertz (THz) waves, and they offer a usable frequency band that is more than 100 times wider than that used by current mobile systems. Such systems that use the THz-wave band will be able to increase the speed of communications up to 100 Gbps or more. Therefore, THz-wave communication systems are expected to be used in such applications as front haul systems in cellular networks, rack-to-rack or inter-rack communications in data centers, instant data downloading systems for 4K or 8K HD video, and so on. This paper describes our indium phosphide (InP)-based high electron mobility transistor (HEMT) technology, THz circuit design techniques, and packaging techniques for constructing compact apparatus, which are being developed by Fujitsu and Fujitsu Laboratories to realize THz-wave communication systems. This paper also reports on a compact 300 GHz receiver capable of receiving a 20 Gbps data stream and its application demo.
3D Packaging Technology to Realize Miniaturization/High-Density and High-Performance Servers (952 KB)
Hideki Kitada, Toshiya Akamatsu, Takeshi Ishitsuka, Seiki Sakuyama, pp.15-22
With LSI micro-fabrication technology reaching its scaling limits, miniaturizing LSIs based on Moore's Law is unable to satisfy the CPU/memory module performance for high-speed and low-power servers. Fujitsu Laboratories has developed a 3D packaging technology that connects between multiple devices in the shortest distance. This technology is a revolutionary next-generation packaging technology for high-performance servers to support Fujitsu's existing information and communications technology (ICT) business. We were the first to verify 3D logic device operation by integrating the following technologies: through silicon via (TSV) technologies, in which signals are connected in the shortest distance between top and bottom stacked LSIs; super multi-pin connection technology for bandwidth expansion; and transmission design technologies considering power integrity and signal integrity (PI/SI) between stacked chips. Further, by optimizing the design of TSV and a redistribution layer (RDL), we have been successful in greatly shortening the connection distance between chips and increasing data transmission volumes, and high-speed transmission of 25 Gbps has been confirmed. Additionally, we have developed solder materials and a process to be used in fine TSV in which large amounts of current flow and connection terminal sections on chips, achieving stable supply of 200-Watt-class power. In this paper, we will discuss the important key technologies in 3D packaging technology for realizing high-performance processors.
Nanocarbon Technology for Development of Innovative Devices (834 KB)
Shintaro Sato, Daiyu Kondo, Shinichi Hirose, Junichi Yamaguchi, pp.23-30
Graphene, a one-atom-thick honeycomb lattice made of carbon, and a carbon nanotube, a rolled-up graphene sheet, have excellent electrical properties, such as high electron mobility and tolerance to a high current density. They also have high thermal conductivity and mechanical strength, and are therefore promising materials for future electronic devices. Facing the limit of scaling (miniaturization) of semiconductor devices represented by silicon transistors, our group is researching ways to apply nanocarbon materials (graphene and carbon nanotubes) to electronics for a breakthrough. In this article, we first explain the electronic states and properties of nanocarbon materials, as well as expectations for applying them that come from their excellent properties. We then describe the method of growing nanocarbon materials, followed by an explanation of our efforts to apply such materials to transistors, interconnects, and thermal interface material (TIM). Finally, we briefly explain a technology to synthesize graphene nanoribbon, a narrow strip of graphene, which we are working on in order to develop devices with superb properties.

Sensing Technology to Support IoT

Millimeter-wave CMOS Transceiver Techniques for Automotive Radar Systems (956 KB)
Yoichi Kawano, Hiroshi Matsumura, Ikuo Soga, Yohei Yagishita, pp.31-37
Recently, advanced driver assistance systems (ADAS) with the keyword of "safety" have attracted attention in the world. Many mega-suppliers (Tier 1) and the others have been carrying out development for safe systems using cameras, lasers, and millimeter-wave radar to realize a self-driving system in the near future. Fujitsu Laboratories has been developing millimeter-wave monolithic microwave integrated circuits (MMICs) and modules for automotive radar systems, and is now interested in MMICs based on complementary metal oxide semiconductors (CMOS). In this paper, we describe millimeter-wave amplifiers and a 4-ch transmitter based on accurate device measurement and modeling techniques using the on-wafer calibration method. A phased locked loop (PLL) which operates at 0.96 GHz/µs, the world's fastest modulation speed, is also discussed.
Mobile Sensor that Quickly and Selectively Measures Ammonia Gas Components in Breath (679 KB)
Osamu Tsuboi, Satoru Momose, Ryozo Takasu, pp.38-43
Amid the increasing trend of aging societies across the world, there are now expectations for healthcare tailored to individuals that helps to more quickly detect diseases and improve lifestyles to ensure health and longevity for the current generation. Therefore, it is thought that it will be effective to use device technology and information and communications technology (ICT) to monitor an index related to the state of the body, easily and continuously in the home, clinic, and such like. We have focused research on diagnostic methods using breath analysis to examine the gaseous components of a person's breath as an indicator of the condition of his or her body, and developed a mobile breath sensor. This paper describes a breath sensor system that can selectively measure the concentration of ammonia that is present in everyone's exhaled breath. By applying the ammonia-adsorbing characteristic of copper(I) bromide films, we successfully developed a sensor that measures tiny amounts of ammonia in a person's breath at a sensitivity differential that is more than treble that of a gas having other living body origins. By using the sensor device, we have developed a breath sensor system. As a result, it has become possible to continuously and easily examine changes in components of the breath in relation to lifestyle without any accompanying pain such as the pain of collecting blood, similar to using a clinical thermometer.

Environment and Energy Devices to Support Green ICT

Artificial Photosynthesis Technology for Solving Environmental and Energy Issues (1.40 MB )
Yoshihiko Imanaka, Toshio Manabe, Toshihisa Anazawa, Hideyuki Amada, pp.44-50
To create a sustainable society that is friendly to the global environment for the future, decreasing the amount of greenhouse gases such as CO2 is an urgent matter, and also producing storable clean energy that does not depend on fossil fuels is demanded. Artificial photosynthesis consisting of a light reaction dependent on a light source and dark reaction not related to it is technology with which oxygen, hydrogen, and organic products are produced artificially by using solar energy, water, and CO2. Recently, this has come to be regarded as an important technology for solving both the environmental and energy issues we face, as described above. Fujitsu has researched this technology as one of the important basic technologies relating to energy and the environment in order to achieve a sustainable human-centric society for the future. This paper introduces basic research regarding materials and devices applied to the light reaction and dark reaction that we are currently investigating in order to develop a highly efficient artificial photosynthesis system producing storable energy by using CO2, water molecules, and electrons generated from a photocatalyst irradiated with solar light.

Human-Friendly Interface Technology

Three-dimensional Wireless Power Transfer Method to Realize Efficient Charging of IoT Devices (664 KB)
Akiyoshi Uchida, Satoshi Shimokawa, Kiyoto Matsui, Hirotaka Oshima, pp.51-56
Many users desire to charge their Internet of Things (IoT) devices such as mobile or wearable devices wirelessly. Wireless power transfer technology using resonant magnetic coupling makes it possible to charge a receiver that is distant from the transmitter. However, the receiver can take various orientations over that distance, and this causes problems, such as an extreme decrease in power transfer efficiency in certain cases. To solve this problem, we developed a method to control the direction of the magnetic field corresponding to the various orientations of the receiver, so that efficient power transfer can be achieved. To control the magnetic field direction, we selected the current path using multiple transmitter coils. As an example of the developed system, we made a transmitter in a table shape with a receiver in a smartphone. With this system, we demonstrated that a smartphone in use can be charged wirelessly by placing it above or on the table, and proved the validity of the three-dimensional (3D) wireless power transfer system. In this article, we explain the 3D wireless power transfer system that we developed. We also introduce various efforts we have made for domestic and international standardization or institutionalization to popularize wireless power transfer systems.