Category Archives: Semiconductors

Global power semiconductor revenues grew year-over-year by 3.9 percent in 2016, reversing a 4.8 percent decline in 2015, according to a recent report from business information provider IHS Markit (Nasdaq: INFO).

All categories of power semiconductors (power discretes, power modules, and power integrated circuits) were up for the year, with the discretes market seeing the biggest jump. Sales in all regions increased, with China revenues topping the list. IHS Markit expects the market to grow by 7.5 percent in 2017, to $38.3 bill and achieve yearly increases through 2021.

Automotive and industrial lead the way

The automotive and industrial segments were particularly strong in 2016, with power semis in automotive growing by 7.0 percent and industrial by 5.0 percent. Advanced driver assistance systems (ADAS) – such as blind-spot detection, collision avoidance, and adaptive cruise control – are moving from luxury to mid-level vehicles, driving double digit increases for power semiconductors in that category.

Power semiconductors, especially power modules and discretes also saw sharp gains as the number of cars equipped with inverter systems for advanced start/stop and hybrid powertrains increased. In particular, power modules for cars and light trucks jumped 29.3 percent in 2016.

In the broad industrial sector the drive for energy efficiency improvement led to growth in renewable energy (solar and wind inverters), building and home control, and factory automation applications. Revenues from home appliances in the consumer segment also grew nicely as advanced motor control systems found their way into white goods, fans, kitchen, and cleaning products.

Despite good gains, other categories were flat to down. Power module sales for industrial motor drives, a large sub-segment, slid 1.1 percent and modules for traction applications were down 17.5 percent for the year.  Power ICs for consumer application declined 4.9 percent while power discretes for lighting applications were off 2.7 percent.

Growth to continue

“The industry megatrends of vehicle electrification, advanced vehicle safety, energy efficiency and connected everything will continue to drive growth over the next five years,” said Kevin Anderson, senior analyst, power management for IHS Markit. “IHS Markit predicts that the compound-average annual growth rate (CAGR) from 2016 – 2021 will be 4.8 percent.  Regionally, the highest growth is projected in China, at 6.0 percent CAGR, followed closely by the rest of Asia including Taiwan, Europe, Middle East and Africa, and the Americas – all with projected growth over 5 percent.”

IC Insights recently released its September Update to The McClean Report.  This 32-page Update included a detailed look at the pure-play foundry market.  Shown below is an excerpt from the Update.

With the rise of fabless IC companies in China, demand for foundry services in that country has also increased.  Figure 1 shows IC Insights’ listing of the top pure-play foundries and their sales to China in 2016 and a forecast for 2017.  In total, pure-play foundry sales in China are expected to jump by 16% this year to about $7.0 billion, more than double the rate of increase for the total pure-play foundry market.  As shown, only about 10% of TSMC’s sales are forecast to go into China in 2017, yet the company is expected to hold the largest share of the China foundry market this year with a 46% share, up two percentage points from 2016.

Figure 1

Figure 1

The Chinese foundry market represented 11% of the total pure-play foundry market in 2015, 12% in 2016, and is forecast to hold a 13% share this year.  As a result of this growth, most pure-play foundries have made plans to locate or expand IC production in mainland China over the next few years. TSMC, GlobalFoundries, UMC, Powerchip, and, most recently, TowerJazz have announced plans to boost their China-based wafer fabrication production.  Most of these new China-based foundry wafer fabs are scheduled to come online in late 2017 or in 2018.  UMC began 40nm production at its 300mm joint venture China fab in November of 2016 and the company is planning to introduce 28nm technology into the fab in the second half of this year with additional expansion plans to come through the end of the decade.

It is well known that China is striving to develop an indigenous semiconductor industry but gaining access to the manufacturing technology has become increasingly difficult.  As a result, many China IC companies and government entities have structured joint ventures or partnerships with foundry companies in order to access leading manufacturing technology.  The partnerships give Chinese companies much needed access to production capacity using first-rate manufacturing technology and provide the foundries with an ongoing market presence and revenue stream within China.

Examples of pure-play foundries that are working to set up new manufacturing plants in China include,

•    UMC is working with Fujian Jin Hua IC Company to construct a 300mm wafer fab in Fujian, China to manufacture DRAM using 32nm process technology developed by UMC.

•    GlobalFoundries joined with the Chengdu Government in 1Q17 to begin building a 300mm wafer fab that will manufacture ICs using mainstream 130nm and 180nm processes.  Completion is set for early 2018.

•    TSMC started construction on a wholly owned $3 billion fab in Nanjing, China that will serve as a foundry that manufactures ICs using 16nm technology.  Production is scheduled to begin in 2H18.

•    TowerJazz signed an agreement with Tacoma Semiconductor to construct a 200mm wafer fab, also in Nanjing, China.  TowerJazz will have access to 50% of the capacity.  Tacoma is responsible for the entire investment of the project.

Advanced Linear Devices Inc. (ALD), a designer of analog semiconductors, today announced a zero-gate threshold voltage EPAD P-Channel MOSFET Array launching the industry’s first precision sub-threshold circuit. The MOSFET currently has the industry’s lowest operating voltage of 0.2 Volt (V) and current of less than one nano amp (nA). These chips enable the operating regions required for the next generations of development in energy harvesting, Internet of Things (IoT) sensors applications.

The ALD310700A/ALD310700 quad zero threshold MOSFET is intended for the development of small signal precision applications utilizing 0.00V Zero Threshold Voltage. The circuit is ideal for designs requiring very low operating voltages of < +0.5V power supplies. Allowing circuits to operate in the subthreshold region for the first time ever, expands the MOSFET’s operating range into never-before achieved signal levels.

The new MOSFET simplifies circuit biasing schemes and reduces component counts while providing greater precision and sensitivity of sensor applications for IoT engineers. The P-Channel MOSFET can work in conjunction with ALD N-Channel Zero Threshold MOSFET devices in matched sensor applications. The ALD310700A/ALD310700 is the P-channel version of the popular ALD110800A/ALD110800 Precision Zero Threshold N-channel device. Together, these two MOSFET series deliver complementary precision performance. These complementary paired devices enable the design of 0.5% precision current mirrors, current sources, and circuits referenced to power or ground sources including differential amplifier input stages, transmission gates and multiplexers.

Notable device features

  •     Precision offset voltages (VOS): 2mV max.; 10mV max.;
  •     Low minimum operating voltage of less than 0.2V;
  •     Ultra-low minimum operating current of less than 1nA:
  •     Matched and tracked temperature characteristics.

“These devices operate at a point with 100 times lower power than comparable MOSFET arrays. More importantly they enable the next generation of applications at power levels and precision that were impossible until now,” said Robert Chao, President, and Founder, Advanced Linear Devices Inc. “These arrays offer circuit designers working on IoT nodes that require matched sensor activity a method to collect power from supercapacitors or deep cycle batteries.”

As an example, some potential energy harvesting sources, such as thermal electric generators that yield just 0.2V, produce such low levels of energy that they are barely useful for driving power in electronic circuitry. The ALD P-Channel Zero-Threshold (VGS(th)=0.00) EPAD MOSFET arrays can be coupled with a low voltage step-up converter to give low-level power sources a greater range as an energy harvesting source.

This device is available in a quad version and is a member of the EPAD® Matched Pair MOSFET Family. The parts can be ordered directly from ALD or DigiKey and Mouser. Prices start at $2.00 at 100 pieces.

The Semiconductor Industry Association (SIA) today announced worldwide sales of semiconductors reached $35.0 billion for the month of August 2017, an increase of 23.9 percent compared to the August 2016 total of $28.2 billion and 4.0 percent more than the July 2017 total of $33.6 billion. All major regional markets posted both year-to-year and month-to-month increases in August, and the Americas market led the way with growth of 39.0 percent year-to-year and 8.8 percent month-to-month. All monthly sales numbers are compiled by the World Semiconductor Trade Statistics (WSTS) organization and represent a three-month moving average.

“Global semiconductor sales were up significantly in August, increasing year-to-year for the thirteenth consecutive month and reaching $35 billion for the first time,” said John Neuffer, president and CEO, Semiconductor Industry Association. “Sales in August increased across the board, with every major regional market and semiconductor product category posting gains on a month-to-month and year-to-year basis. Memory products continue be a major driver of overall market growth, but sales were up even without memory in August.”

Year-to-year sales increased in the Americas (39.0 percent), China (23.3 percent), Asia Pacific/All Other (19.5 percent), Europe (18.8 percent), and Japan (14.3 percent). Month-to-month sales increased in the Americas (8.8 percent), China (3.7 percent), Japan (2.8 percent), Asia Pacific/All Other (2.2 percent), and Europe (0.6 percent).

“With about half of global market share, the U.S. semiconductor industry is the worldwide leader, but U.S. companies face intense global competition,” said Neuffer. “To allow our industry to continue to grow and innovate here at home, policymakers in Washington should enact corporate tax reform that makes the U.S. tax system more competitive with other countries. The corporate tax reform framework released last week by leaders in Congress and the Trump Administration is an important step forward. We look forward to working with policymakers to enact corporate tax reform that strengthens our industry and the U.S. economy.”

Aug 2017

Billions

Month-to-Month Sales                              

Market

Last Month

Current Month

% Change

Americas

6.94

7.55

8.8%

Europe

3.20

3.22

0.6%

Japan

3.04

3.13

2.8%

China

10.68

11.08

3.7%

Asia Pacific/All Other

9.77

9.98

2.2%

Total

33.63

34.96

4.0%

Year-to-Year Sales                         

Market

Last Year

Current Month

% Change

Americas

5.43

7.55

39.0%

Europe

2.71

3.22

18.8%

Japan

2.73

3.13

14.3%

China

8.99

11.08

23.3%

Asia Pacific/All Other

8.35

9.98

19.5%

Total

28.22

34.96

23.9%

Three-Month-Moving Average Sales

Market

Mar/Apr/May

Jun/Jul/Aug

% Change

Americas

6.27

7.55

20.5%

Europe

3.11

3.22

3.8%

Japan

2.95

3.13

6.0%

China

10.25

11.08

8.1%

Asia Pacific/All Other

9.43

9.98

5.9%

Total

31.99

34.96

9.3%

A sea of spinning electrons


October 3, 2017

Picture two schools of fish swimming in clockwise and counterclockwise circles. It’s enough to make your head spin, and now scientists at Rutgers University-New Brunswick and the University of Florida have discovered the “chiral spin mode” – a sea of electrons spinning in opposing circles.

“We discovered a new collective spin mode that can be used to transport energy or information with very little energy dissipation, and it can be a platform for building novel electronic devices such as computers and processors,” said Girsh Blumberg, senior author of the study and a professor in the Department of Physics and Astronomy in Rutgers’ School of Arts and Sciences.

Collective chiral spin modes are propagating waves of electron spins that do not carry a charge current but modify the “spinning” directions of electrons. “Chiral” refers to entities, like your right and left hands, that are matching but asymmetrical and can’t be superimposed on their mirror image.

The study, led by Hsiang-Hsi (Sean) Kung, a graduate student in Blumberg’s Rutgers Laser Spectroscopy Lab, was published in Physical Review Letters. Kung used a custom-made, ultra-sensitive spectrometer to study a prototypical 3D topological insulator. A microscopic theoretical model that predicts the energy and temperature evolution of the chiral spin mode was developed by Saurabh Maiti and Professor Dmitrii Maslov at the University of Florida, strongly substantiating the experimental observation.

The blue and red cones show the energy and momentum of surface electrons in a 3D topological insulator. The spin structure is shown in the blue and red arrows at the top and bottom, respectively. Light promotes electrons from the blue cone into the red cone, with the spin direction flipping. The orderly spinning leads to the chiral spin mode observed in this study. Credit: Hsiang-Hsi (Sean) Kung/Rutgers University-New Brunswick

The blue and red cones show the energy and momentum of surface electrons in a 3D topological insulator. The spin structure is shown in the blue and red arrows at the top and bottom, respectively. Light promotes electrons from the blue cone into the red cone, with the spin direction flipping. The orderly spinning leads to the chiral spin mode observed in this study.
Credit: Hsiang-Hsi (Sean) Kung/Rutgers University-New Brunswick

In a vacuum, electrons are simple, boring elementary particles. But in solids, the collective behavior of many electrons interacting with each other and the underlying platform may result in phenomena that lead to new applications in superconductivity, magnetism and piezoelectricity (voltage generated via materials placed under pressure), to name a few. Condensed matter science, which focuses on solids, liquids and other concentrated forms of matter, seeks to reveal new phenomena in new materials.

Silicon-based electronics, such as computer chips and computers, are one of the most important inventions in human history. But silicon leads to significant energy loss when scaled down. One alternative is to harness the spins of electrons to transport information through extremely thin wires, which in theory would slash energy loss.

The newly discovered “chiral spin mode” stems from the sea of electrons on the surface of “3D topological insulators.” These special insulators have nonmagnetic, insulating material with robust metallic surfaces, and the electrons are confined so they move only on 2D surfaces.

Most importantly, the electrons’ spinning axes are level and perpendicular to their velocity. Chiral spin modes emerge naturally from the surface of such insulating materials, but they were never observed before due to crystalline defects. The experimental observation in the current study was made possible following the development of ultra-clean crystals by Rutgers doctoral student Xueyun Wang and Board of Governors Professor Sang-Wook Cheong in the Rutgers Center for Emergent Materials.

The discovery paves new paths for building next generation low-loss electronic devices.

By Dr. Jeongdong Choe, Senior Technical Fellow, TechInsights

There has been a great deal of speculation around the composition of Intel’s Optane™ XPoint memory technology: PCM or ReRAM, selector, layouts, patterning technology, technology node, multi-stacked cell structure, die floor plan, interconnection to each electrode (wordlines and bitlines), functional blocks, scalability and process integration.

TechInsights set about to find answers. We have analyzed Optane’s memory cell structure, materials, cell array and memory peripheral array design, layouts, process flow and circuitry. Our Advanced CMOS Essential (ACE) analyses on Intel’s XPoint memory presents our complete findings and market trend predictions. The following paragraphs present some of the highlights.

Intel XPoint memory is based on PCM and selector memory (storage) cell elements. GST-based PCM, Ge-Se-As-Si based Ovonic Threshold Switch (OTS) and two memory cell stacked array architecture are common across Intel’s and Micron’s XPoint technologies.

We examined effective memory cell area efficiency vs. memory array efficiency, and compared it to current DRAM and NAND products. In our previous analysis on XPoint memory die, we found that memory density per die is 0.62 Gb/mm2 and memory efficiency is over 91%. The memory array efficiency, however, may not represent the reality because the memory peripheral and CMOS circuitry cover most of the die area.

We can define the effective cell area efficiency as a ratio of the real area of the cell memory elements (storage) to the total die area. For example, the effective memory cell area efficiency on Toshiba 15 nm 2D planar NAND is 43.9% due to excluding BC, CSL, SSL, GSL dummy wordlines and peripheral area on a die, while memory array efficiency is 72%. Figure 1 shows comparison of the effective memory cell area efficiency for 2D/3D NAND products from Toshiba/SanDisk (Western Digital), Micron/Intel, SK Hynix and Samsung, and 3D XPoint (OptaneTM from Intel).

Figure 1. A comparison of effective memory cell area efficiency on 2D/3D NAND and XPoint memory

Figure 1. A comparison of effective memory cell area efficiency on 2D/3D NAND and XPoint memory

When it comes to the effective unit cell size per 1 bit, NAND flash devices have been scaled down from 2D NAND (320 nm2) to 48L 3D NAND (145.8 nm2) or even to 64L 3D NAND (88.5 nm2) for Toshiba NAND products, while Intel OptaneTM two cell stacked XPoint memory has 800 nm2 (effectively 2F2) (Figure 2).

Figure 2. A comparison of effective unit cell area per bit on 2D/3D NAND and XPoint memory

Figure 2. A comparison of effective unit cell area per bit on 2D/3D NAND and XPoint memory

A comparison of memory density with DRAM products shown in Figure 3 illustrates that XPoint has higher memory density (0.62 Gb/mm2) than Samsung 1x nm (0.19 Gb/mm2), SK Hynix 2y nm (0.15 Gb/mm2) and Micron 20 nm (0.094 Gb/mm2) DRAM dice. Micron announced that the memory density of XPoint would be ten times higher than commercial DRAM products. This is true if we compare it with 30 nm class DRAM products, because most of the 30 nm class DRAM products from major DRAM manufacturers have 0.06 Gb/mm2 memory density. The first commercial XPoint memory die has three times (vs. Samsung 1x DRAM) or six times (vs. Micron 20 nm DRAM) higher memory density than those of current DRAM products.

Figure 3. A comparison of die size and memory density on DRAM (25nm/20nm/18nm) and XPoint memory

Figure 3. A comparison of die size and memory density on DRAM (25nm/20nm/18nm) and XPoint memory

We found that Intel introduced some innovative and compelling technologies on their first XPoint products such as PCM/OTS stack used for memory elements, GST based PCM, Ge-Se-As-Si based OTS and carbon based conductor and 2-bit cell stacked memory array with three electrodes. Intel successfully used a 20nm SADP double patterning technology to build a very uniform GST-based PCM/OTS memory square/island. Complete details on the of TechInsights’ XPoint memory analysis can be found here.

Click here to hear more from Dr. Choe and his TechInsights colleagues on 3D NAND.

Today, SEMI announced the lineup of keynotes coming to SEMICON Japan’s “SuperTHEATER” ─ focusing on the future of the electronics manufacturing supply chain. SEMICON Japan 2017, the largest exhibition in Japan for electronics manufacturing, will take place at Tokyo Big Sight in Tokyo on December 13-15. Registration is now open for the exhibition and programs.

With the theme “Dreams Start Here,” SEMICON Japan 2017 will bring together the connections between people, technologies and businesses across the electronics manufacturing supply chain ─ extending to the internet of things (IoT) applications that inspire the dreams that shape the future.

Japan has the world’s third-largest 300mm wafer installed fab capacity and the world’s largest 200mm and smaller wafer fab capacity (including discrete devices production). Japan also supplies one third of the semiconductor equipment and more than half of the semiconductor materials that are purchased in the global market.

The SuperTHEATER offers nine keynote forums, all with simultaneous English-Japanese translation. On December 13, keynotes at SEMICON Japan’s SuperTHEATER include:

  • Opening Keynotes ─ Visions of the Game Changing Era
    • Soft Bank:  Ken Miyauchi, president and CEO, “The Information Revolution beyond the Singularity”
    • Qualcomm Technologies: Raj Talluri, senior VP of product management, “Qualcomm Viewpoint: Accelerating the Internet of Things”
       
  • Semiconductor Executive Forum ─ Growth Strategy in New Business Environment
    • TowerJazz Semiconductor: Russell Ellwanger, CEO, “Value Creation”
    • SMIC: Haijun Zhao, CEO, “Considerations in Developing Manufacturable IC Technologies”
    • Micron Technology: Wayne Allan, senior VP of global manufacturing, “Enabling Smart Manufacturing in Today’s Industry 4.0”

The SEMI Market Forum, also on December 13, will offer presentations from IHS Markit and SEMI, with the theme “In the Light and Shadow of Awaking China”

Additional SEMICON Japan 2017 highlights include:

  • IT/AI Forum on U.S. companies’ artificial intelligence strategies
  • IoT Global Trends Forum on semiconductors for IoT
  • IoT Key Technology Forum on Smart Transportation
  • Manufacturing Innovation Forum n “Manufacturing Technology for the Diversified Future”
  • Electronics Trends
  • Mirai (the Future) Vision

 

For more information and to register for SEMICON Japan, visit www.semiconjapan.org/en/

COMET Group, a global provider of high-quality systems, components and services such as x-ray, ebeam and radio frequency technologies, today announced the opening of Lab One, its customer-centric technology and application center in San Jose, CA.

Scheduled to open October 4th, Lab One will bring Comet Group’s three core technologies under one roof for the first time:

  • RF power – Comet Plasma Control Technologies (PCT) designs and manufactures the technology used to make semiconductors and is used by leading chip manufacturers that power the industry’s most popular mobile devices (e.g. Apple, Samsung) and electronics (e.g. flat panel displays)
  • X-ray – Yxlon’s industrial X-ray and computed tomography – systems and services enable customers to improve the quality of their products and processes by non-destructive testing, measuring and decision support in industries such as electronics, automotive, aerospace, medtech, science and new technologies. They are based on highly compact Comet x-ray components and sources
  • ebeam – ebeam technology inactivates harmful pathogens that can cause food borne illnesses and provides safe, environmentally friendly packaging materials that reduce waste and improve food security

The working Lab and testing environment will act as an extension to many leading Silicon Valley businesses – providing access to a variety of testing and inspection services, as well as opportunities to collaborate with Comet Group’s industry experts, who will be available for consultation, brainstorming and problem solving.

“Our new Lab One facility can save local businesses time by providing local inspection services, save them money by finding costly flaws, and solve their logistic inspection services headaches with quick answers to their non-destructive test needs,” said Paul Smith, Sr. Vice President at Comet Technologies USA. “It’s a place where ideas are jointly transformed into solutions and solutions into business success.” 

With pioneering solutions for a wide range of industries, Comet Group will support its clients by bringing greater safety and security, mobility, sustainability and efficiency to numerous areas of life.

By Yoichiro Ando, SEMI Japan

Shinzo Abe, the prime minister of Japan, plans to stage a Robot Olympics in 2020 alongside the summer Olympic Games to be hosted in Tokyo. Abe said he wants to showcase the latest global robotics technology, an industry in which Japan has long been a pioneer. Japan’s Robot Strategy developed by the Robot Revolution Initiative Council plans to increase Japanese industrial robot sales to 1.2 trillion JPY by 2020. This article discusses how the robotics industry is not just a key pillar of Japan’s growing strategy but also a key application segment that may lead Japan’s semiconductor industry growth.

Japan leads robotics industry

According to International Federation of Robotics (IFR), the 2015 industrial robot sales increased by 15 percent to 253,748 units compared to the 2014 sales. Among the 2015 record sales, Japanese companies shipped 138,274 units that represent 54 percent of the total sales according to Japan Robot Association (JARA). The robotics companies in Japan include Yaskawa Electric, Fanuc, Kawasaki Heavy Industries, Fujikoshi and Epson.

Source: International Federation of Robotics (global sales) and Japan Robot Association (Japan shipment)

Source: International Federation of Robotics (global sales) and Japan Robot Association (Japan shipment)

The automotive industry was the most important customer of industrial robots in 2015 that purchased 97,500 units or 38 percent of the total units sold worldwide. The second largest customer was the electrical/electronics industry (including computers and equipment, radio, TV and communication devices, medical equipment, precision and optical instruments) that showed significant growth of 41 percent to 64,600 units.

Semiconductors devices used in robotics industry

Robotics needs semiconductor devices to improve both performance and functionality. As the number of chips used in a robot increases and more advanced chips are required, the growing robotics market is expected to generate significant semiconductor chip demands.

FEA-RO-IA-R2000-SpotWeld-3

Semiconductor devices in robots are used for collecting information; information processing and controlling motors and actuators; and networking with other systems.

  • Sensing Devices: Sensors are used to collect information including external information such as image sensors, sound sensors, ultrasonic sensors, infrared ray sensors, temperature sensors, moisture sensors and pressure sensors; and movement and posture of the robot itself such as acceleration sensors and gyro sensors.

    Enhancing these sensors’ sensitivity would improve the robot performance. However, for robot applications, smaller form factors, lighter weight, lower power consumption, and real-time sensing are also important. Defining all those sensor requirements for a specific robot application is necessary to find an optimal and cost-effective sensor solution.

    In addition, noise immunity is getting more important in selecting sensors as robot applications expand in various environments that include noises. Another new trend is active sensing technology that enhances sensors’ performance by actively changing the position and posture of the sensors in various environments.

  • Data Processing and Motor Control Devices: The information collected by the sensors is then processed by microprocessors (MPUs) or digital signal processors (DSPs) to generate control signals to the motors and actuators in the robot. Those processors must be capable of operating real-time to quickly control the robot movement based on processed and analyzed information. To further improve robot performance, new processors that incorporate artificial intelligence (AI) and ability to interact with the big data cloud database are needed.
  • As robotics is adapted to various industry areas as well as other services and consumer areas, the robotics industry will need to respond to multiple demands. It is expected that more field programmable gate arrays (FPGAs) will be used in the industry to manufacture robots to those demands.

    In the control of motors and actuators, power devices play important roles. For precise and lower-power operation of the robot, high performance power devices using high band gap materials such as Silicon Carbide and Gallium Nitride will likely used in the industrial applications.

  • Networking Devices: Multiple industrial robots used in a production line are connected with a network. Each robot has its internal network to connect its components. Thus every robot is equipped with networking capability as a dedicated IC, FPGA or a function incorporated in microcontrollers.

Ando--industrial-automation

Smart Manufacturing or Industry 4.0 requires all equipment in a factory to be connected to a network that enables the machine-to-machine (M2M) communication as well as connection to the external information (such as ordering information and logistics) to maximize factory productivity. To be a part of such Smart Factories, industrial robots must be equipped with high-performance and high-reliability network capability.

Opportunities for semiconductor industry in Japan

Japanese semiconductor companies are well-positioned in the key semiconductor product segments for robotics such as sensors, microcontrollers and power devices. These products do not require the latest process technology to manufacture and can be fabricated on 200mm or smaller wafers at a reasonable cost. Japan is the region that holds the largest 200mm and smaller wafer fab capacity in the world and the lines are quite versatile in these product categories.

The robotics market will likely be a large-variety and small-volume market. Japanese semiconductor companies will have an advantage over companies in other regions because they can collaborate with leading robotics companies in Japan from early stages of development. Also, Japan may lead the robotics International Standards development which would be another advantage to Japanese semiconductor companies.

For more information about the robotics and semiconductor, attend SEMICON Japan on December 13 to 15 in Tokyo. Event and program information will be available at www.semiconjapan.org soon.

Quantum dots are nanometre-sized semiconductor particles with potential applications in solar cells and electronics. Scientists from the University of Groningen and their colleagues from ETH Zürich have now discovered how to increase the efficiency of charge conductivity in lead-sulphur quantum dots. Their results will be published in the journal Science Advances on 29 September.

Quantum dots are clusters of some 1,000 atoms which act as one large ‘super-atom’. The dots, which are synthesized as colloids, i.e. suspended in a liquid like a sort of paint, can be organized into thin films with simple solution-based processing techniques. These thin films can turn light into electricity. However, scientists have discovered that the electronic properties are a bottleneck. ‘Especially the conduction of holes, the positive counterpart to negatively charged electrons’, explains Daniel Balazs, PhD student in the Photophysics and Optoelectronics group of Prof. Maria A. Loi at the University of Groningen Zernike Institute for Advanced Materials.

Stoichiometry

Loi’s group works with lead-sulphide quantum dots. When light produces an electron-hole pair in these dots, the electron and hole do not move with the same efficiency through the assembly of dots. When the transport of either is limited, the holes and electrons can easily recombine, which reduces the efficiency of light-to-energy conversion. Balazs therefore set out to improve the poor hole conductance in the quantum dots and to find a toolkit to make this class of materials tunable and multifunctional.

‘The root of the problem is the lead-sulphur stoichiometry’, he explains. In quantum dots, nearly half the atoms are on the surface of the super-atom. In the lead-sulphur system, lead atoms preferentially fill the outer part, which means a ratio of lead to sulphur of 1:3 rather than 1:1. This excess of lead makes this quantum dot a better conductor of electrons than holes.

Thin films

In bulk material, transport is generally improved by ‘doping‘ the material: adding small amounts of impurities. However, attempts to add sulphur to the quantum dots have failed so far. But now Balazs and Loi have found a way to do this and thus increase hole mobility without affecting electron mobility.

Many groups have tried to combine the addition of sulphur with other production steps. However, this caused many problems, such as disrupting the assembly of the dots in the thin film. Instead, Balazs first produced ordered thin films and then added activated sulphur. Sulphur atoms were thus successfully added to the surface of the quantum dots, without affecting the other properties of the film. ‘A careful analysis of the chemical and physical processes during the assembly of quantum dot thin films and the addition of extra sulphur were what was needed to get this result. That’s why our group, with the cooperation of our chemistry colleagues from Zürich, was successful in the end.’

Devices

Loi’s team is now able to add different amounts of sulphur, which enables them to tune the electric properties of the super-atom assemblies. ‘We now know that we can improve the efficiency of quantum dot solar cells above the current record of 11%. The next step is to show that this method can also make other types of functional devices such as thermoelectric devices.’ It underlines the unique properties of quantum dots: they act as one atom with specific electric properties. ‘And now we can assemble them and can engineer their electrical properties as we wish. That is something which is impossible with bulk materials and it opens new perspectives for electronic and optoelectronic devices.’