Gallium's melting point is 29.76 °C; it has a high boiling point. Not found in a pure form in nature, it was discovered in the 1870s and is derived from bauxite and zinc ores. Its -nitride compound is used in semiconductors. It is produced in France, Russia, Germany and Hungary. Image Source: The Tomus Arcanum.
It is ironic that as technology reaches quantum levels to make the virtual and the artificial ever more real, progress is slowed by the inherent limits of physical reality. Until recently, computing power increased at Moore's Law rates. But now, we are reaching the end of the Silicon era. Designers have begun to hit a wall because as silicon chips get smaller, they also get hotter. NYT:
"The warning signs began a decade ago, when Patrick P. Gelsinger, then Intel’s chief technology officer, warned that if the trends continued, microprocessor chips would reach the temperature of the sun’s surface by 2011."
In certain corners of the economy, there is no recession, if you bother to look. Vast amounts of money are being poured into the search for silicon's replacement. Tech giants are exploring alternatives such as carbon nanotubes and graphene (see also here and here), indium gallium arsenide (see also here), vanadium oxide bronze, molybdenite, silicon-germanium, and silicon carbide. For citizens weathering economic slowdowns in Europe, consider that in January 2013, the European Union awarded two €1 billion grants in its Future and Emerging Technologies (FET) program to fund 10 years of research in two R&D sectors; the first grant is dedicated to exploring the potential of graphene as a semiconductor; the second grant will support mapping of the human brain. (Why, oh why, do I have the dismal feeling that these two projects will intersect?) IBM has looked into using liquid transistors, with chemical reactions used to switch between conducting and nonconducting states, or between '1' and '0.' The University of Nebraska is researching ferroelectric materials such as barium titanate. In May 2013, the UK government awarded NXP a £2 million grant to develop a silicon semiconductor replacement, with a focus on gallium nitride. ABI Research director Lance Wilson remarks: "Gallium Nitride (GaN) increased its market share in 2010. It is expected to do the same in 2011. Although its adoption hasn’t been as rapid as originally expected, it is nonetheless forecast to be a significant force by 2016."
Today's post concerns the future of gallium nitride (GaN) as the next possible semiconductor. In May 2009, the European Space Agency trumpeted GaN's superior conducting abilities which could launch the communications revolution to new levels:
Gallium nitride is a semiconductor tipped for a bright future. Already widely employed as a light source – being used to illuminate London’s Buckingham Palace and other European landmarks – its high power capacity could spark a space-based communications revolution, promising a five- to ten-fold improvement in satellite signal strength and data rates. Generally regarded as the most promising semiconductor since silicon, gallium nitride (GaN) works better at much higher voltages and temperatures than silicon or the widely-used gallium arsenide (GaAs). Significantly for space, GaN is also inherently radiation-resistant.
A Gallium Nitride transistor: 25 W, 5.5 - 8.5 GHz, GaN MMIC, Power Amplifier. Image Source: Cree.
Caption for the above photograph: "Cree’s CMPA5585025F is a gallium nitride (GaN) High Electron Mobility Transistor (HEMT) based monolithic microwave integrated circuit (MMIC). GaN has superior properties compared to silicon or gallium arsenide, including higher breakdown voltage, higher saturated electron drift velocity and higher thermal conductivity. GaN HEMTs also offer greater power density and wider bandwidths compared to Si and GaAs transistors. This MMIC is available in a 10 lead metal/ceramic flanged package for optimal electrical and thermal performance."
Blue LEDs with Gallium Nitride components. Image Source: treehugger.
Caption for the above photograph: "A breakthrough in producing light emitting diodes could see LED production costs tumble as much as 75%. That's thanks to research by a startup called Bridgelux, which has resulted in a radical shift--Gallium-nitride LEDs can now be grown on silicon substrates for the first time in a "commercial grade." The tech leverages the huge, ultra precise and far cheaper silicon wafers that are used in silicon chip manufacture instead of the smaller, more expensive sapphire ones. The breakthrough has been to successfully grow white LEDs on a silicon substrate to create devices that produce 135 lumens per watt of electrical power--well above what typical CFL bulbs can offer, and around 10 times better than old incandescent bulbs."
Plessey's High Brightness LEDs have GaN components. Image Source: Plessey.
Dow Corning joins GaN initiative (April 2011): "GaN could prove useful in a wide range of applications." Image Source: Dow Corning via RSC.
Caption for the above photograph: "Silicon company Dow Corning has agreed to join an R&D program led by Belgian research centre Imec that aims to take the production of semiconductor materials based on gallium nitride (GaN) to manufacturing scale. According to Imec, GaN materials provide better electron mobility, higher breakdown voltages and good thermal conductivity properties, leading to higher switching efficiencies compared with silicon alternatives."
Great2 Project Logo: GaN is the cornerstone of European Space Agency hopes for increased competitiveness with American space projects. The Americans have restricted trade in GaN technology. Image Source: ESA.
Caption for the above logo (May 2009): "ESA has identified GaN as a ‘key enabling technology’ for space, and has established the ‘GaN Reliability Enhancement and Technology Transfer Initiative’ (GREAT2), bringing together leading research institutes and manufacturing industry to set up an independent European supply chain to manufacture high-quality GaN devices for space applications.'We want to develop this capability in Europe in order to control our own technological destiny and ensure the competitiveness of European space industry,' explains Andrew Barnes of GREAT2. 'The aim is to improve state-of-the-art products and to develop new applications for wide-band gap semiconductors. Sourcing from overseas is not always feasible because GaN technology is restricted by the US International Traffic in Arms Regulation (ITAR) or subject to end-user license agreements, meaning its procurement cannot be guaranteed.''"
Gallium Nitride also has military applications. In 2005, the American defense contractor Raytheon was awarded a three-year, $26.9 million Defense Advanced Research Projects Agency (DARPA) contract to develop GaN for semiconductor use. The Canadian company Advantech described GaN's military applications in terms of radar, satellites, electronic warfare, high security communications systems and micro-devices. ABI Research comments:
Other than wireless infrastructure, the vertical market showing the strongest uptick in the RF power semiconductor business has been the military, which Wilson describes as being now “a very significant market.” While the producers of these devices are located in the major industrialized countries, the military market is now so global that equipment buyers can come from anywhere.
Todd had been working at Singapore's Institute of Microelectronics (IME); while at IME, Todd was apparently pressed to share his knowledge of GaN, derived from work in the US, with an IME Chinese partner company, which was probably Huawei. Todd became uncomfortable with his role. His friends and family noticed that he became increasingly stressed at work and began attending church regularly, which he had not done before. He told his father that he had been naive about how his expertise was being exploited. Eventually, he resigned. He died on the day before his return to America. The cause of his death was ruled suicide by hanging. But an American pathologist who later saw photos of Todd's body believed he was garrotted and that his hands showed self-defense injuries. Someone had also checked Todd's external hard drive after his body was found and deleted the file that contained the recipe for enhancing a GaN chip.
The FT report claimed that Todd possessed American knowledge of how to harness gallium nitride for computing and military purposes - and through his work, he also knew of Chinese access to that information:
This report was followed by an FT report on 17 February 2013 in which Singaporean police defended their investigation. You can see a summary of events around Todd's death here. In June 2013, Todd's family issued an open letter to the media; they insist he was murdered and attached photos and documents to support their claim; officials deny this conclusion and argue that the family's publicity efforts and an AP article which was circulated by American media are "inaccurate, misleading and mischievous:[A]n external hard drive ... [gave Shane Todd's family] a back-up of ... [Todd's] computer files, including his work at IME, and a timetable and plan for a project that apparently involved IME and Huawei Technologies, the Chinese telecom giant.
The plan lays out how, from 2012 to the end of 2014, IME and Huawei would “co-develop” an amplifier device powered by gallium nitride (GaN), a semiconductor material able to withstand extreme heat and power levels well beyond silicon. GaN devices have commercial use in lighting as well as high-powered transistors for mobile phone base stations. They also have tremendous military potential, and major US defence contractors – including Northrup-Grumman and Raytheon – have pursued significant research and development in GaN for use in radar and satellite communications. ...
Steven Huettner, who has worked on defence projects for more than 30 years in the US, much of that at Raytheon Missile Systems, also reviewed the “Huawei” project plan, and described it as “disturbing”. The project could be aimed at producing high-powered transmitters for mobile phone towers, he acknowledged, but the specifications “jump out at you”. The project “absolutely has military potential”. Huettner said, in his opinion, “an obvious use would be for high-powered radar that could enhance … military capability”. ...
Within weeks of returning from Veeco, Shane Todd seemed increasingly stressed. Until then, Shane “was a typical Californian. He loved life,” said one friend. But in February 2012, friends and Shane’s parents heard that he was uneasy about a work project. In his long, weekly calls through Skype to his parents, Shane said he was collaborating with a Chinese company at IME and felt that representatives asked technical questions and then spoke in Mandarin to exclude him. “I am being asked to do things with a Chinese company that make me uncomfortable,” Mrs Todd recalled him saying. “He said he felt he was being asked to compromise American security.”
Among her sons, Shane was the most private, Mrs Todd said, so she tried not to pry. But Shane complained frequently about IME, sometimes adding that he was stressed about the Chinese project. “Mom, I’m going to call you every week, and if you don’t hear from me for a week, call the American embassy,” Mrs Todd recalled him as saying. She worried that Shane was depressed – much as he had been during university – and she offered to fly to Singapore. He responded: “Mom, I’m not depressed. I’m anxious.” He said she needn’t come, she recalled.
Several times, he told his parents that he felt he was under threat because of his work with the Chinese. Mr Todd tried to talk Shane into coming home. Shane said no, he had an obligation to IME. “I remember, vividly, him saying to me, ‘I am so naive,’” Mr Todd said. “He thought he had been trained for one purpose that was above board. Then he realised he was being asked to do stuff that could harm his country’s national security.” ...
The Todds and the consular officer were ushered into an office where they met Detective Muhammad Khaldun. He read aloud a police description of how Shane had hanged himself then handed over two printouts of suicide notes, which the detective said were found on Shane’s computer. One was addressed “Dear everyone”, another “Dear Mom and Dad”, and there were three brief ones to his girlfriend, his brothers, and “friends”. The police told the Todds that they had Shane’s computer, mobile phone and appointment book, all found in the apartment.
Mrs Todd read the notes and handed them back to the detective. “My son might have killed himself, but he did not write this,” she said with some calm.
The notes were surprising, she said later. One praised IME and its management. Another apologised for being a burden to his family. Neither sounded like Shane. One, Shane had never been a burden – “he had excelled at everything he put his mind to,” Mrs Todd said. Two, “he hated the way IME was run and the way top management treated people.” Shane’s girlfriend later said she was sure Shane’s last moments were not spent lauding IME. “He hated his job,” she said.
IME’s director, Dim-Lee Kwong, is an American who was recently awarded Singapore’s highest honour for contributions to the country’s research and development. Kwong declined to be interviewed about Shane Todd but sent this statement: “As the matter pertaining to Shane’s demise is still under police investigation, IME is unable to comment on the queries that you have raised.”
Before the Todds buried Shane in Pomona, California, where his grandfather and grandparents are buried, they looked hard at his body – at a small bump on his forehead, bruises on his hands, and the trauma around his neck. They read the official autopsy report supplied by the Singapore police. No drugs or alcohol in Shane’s blood. Cause of death: “Asphyxia due to hanging”. Still, the Todds simply couldn’t believe that Shane took his own life.
The Todds therefore asked the mortuary to photograph Shane’s body, in the coffin, and they sent those snapshots to a pathologist recommended by a family member. Dr Edward H. Adelstein, chief of pathology at the Harry S. Truman Veterans Hospital in Missouri, examined the photos and autopsy report and wrote a review that stoked the Todds’ suspicions. Adelstein said Shane’s deeply bruised knuckles and hands should have been listed in the original autopsy. He also said the neck wounds did not look like injuries from a suicide but indicated a rapid death. He suggested a scenario far different to that outlined by the Singapore authorities: Shane fought an attacker and died by a garrotting.
The Todds sent the assessment to Detective Khaldun, who consulted the Singapore pathologist. The latter sent back a detailed dismissal of Adelstein’s review. The hands bore evidence of post-mortem pooling of blood, he wrote. Dr Adelstein had not seen the body and he did not know the difference between “findings of hanging as opposed to … garrotting”.
The Todds were left unconvinced. Then Shane’s father made an unexpected discovery. Two weeks after Shane’s funeral, he looked at the small “speaker” taken from Shane’s home and realised it was an external hard drive. He sent it to a computer analyst recommended by Mrs Todd’s brother. Ashraf Massoud works at Datachasers, a data recovery firm in Riverside, California, and he made several discoveries, which he explained to the FT.
Massoud said he could determine that on June 22 – Shane’s last day at IME – thousands of work files were transferred to the hard drive between 11am and 5.09pm. It was reasonable to think that Shane was creating a back-up from his computer, he said.
Hours later, in the middle of the night, someone went into Shane’s hard drive and accessed five folders, all labelled IME. That happened quickly, between 3.40am and 3.42am on Saturday, June 23. Since the time of Shane’s death is uncertain, Massoud could not say who looked at the IME files.
But Massoud found activity, again, on several more IME files on the night of June 27, three days after Shane’s body was found. He said someone looked at IME folders – including one labelled “Supervisor” and one labelled “Goal Setting” – between 8.38pm and 8.40pm that Wednesday. One file in particular was opened and closed but closed improperly so that a “shadow” file was created. That shadow file was then deleted by the same person. Massoud located the original file on the drive – it was a PowerPoint presentation of the “Layer structure and summary of Veeco grown HEMT wafer”. This contains the scientific formula – a specific recipe – for enhancing a GaN chip.
Massoud said his forensic findings “cannot be 100 per cent conclusive” without reviewing Shane’s computer – which the police retain. But he told the FT: “In that two-minute window, someone is perusing. Something is happening. And it’s not automated, it’s a person.”
In their letter, the Todds said they want to use the case to “alert ordinary citizens and elected officials of the dangers associated with the illegal transfer of technology and to show how far some foreign companies and governments will go to protect clandestine work or international reputation”.The finding of an inquiry by the Singaporean Coroner on Todd's death is due in July 2013.
Shane Todd in Singapore. Image Source: Todd family via FT via Today Online.