Gallium nitride: Tech behind the headlines

Energy efficiency is critical in IT, which is why gallium nitride innovations are valuable as these help lower power consumption and function as a good power amplifier for applications such as mobile phones and base stations.
Written by Kevin Kwang, Contributor

Gallium nitride (GaN) vaulted into the spotlight over the weekend following the Financial Times' report on the death of American engineer Shane Todd and how it may be linked to his research into the technology. Innovations in the GaN space are helping power today's mobile broadband environment and improving energy efficiency in other areas of IT, which makes it an invaluable resource to develop and own.
Market research firm Infonetics illustrated the need for innovations in the mobile broadband space when in June last year it estimated the number of mobile broadband subscribers will reach 2.6 billion, which is an increase of more than 300 percent from 2011's 846 million, by 2016.
"We anticipate Asia-Pacific to account for over half of the world's mobile broadband subscribers by 2016 while Latin America will see the fastest growth," said Infonetics analyst Stephane Teral in the report.

GaN's role in telecommunications

Additionally, a research report released in January 2012 by three Fujitsu engineers, for example, highlighted that base stations are key to mobile wireless communications systems with a higher capacity and faster speed such as Long Term Evolution (LTE) networks. These base stations help make network systems easy to install and reduce maintenance costs, but to do so, they require technologies for reducing the size and power consumption.

"As compared with the conventional semiconductors such as silicon (Si) and gallium arsenide (GaAs), GaN is less prone to electric field breakdown, which allows it to operate at a high voltage."

Gallium nitride high electron mobility transistor (GaN-HEMT) was identified by the three engineers--Toshihide Kikkawa, Kazukiyo Joshin and Masahiro Kanamura--as a "key technology" to achieve higher efficiency and, thus, lower power consumption for these base stations.
"As compared with the conventional semiconductors such as silicon (Si) and gallium arsenide (GaAs), GaN is less prone to electric field breakdown, which allows it to operate at a high voltage," the research noted.
Singapore's Institute of Microelectronics (IME), which hired Shane Todd and had him head up a GaN device research team, also said gallium nitride has been an active research topic for the microelectronics industry, academia and research organizations globally "for many years".
Patrick Lo, deputy executive director for research at IME, told ZDNet Asia that in power electronics, the class of material GaN is in can deliver power much more efficiently than conventional methods and systems. In terms of application, he said GaN technology can possibly be applied to power amplifiers in mobile phones and mobile network base stations, the latter of which has an impact on the use of mobile Internet in the market.
He added actual devices based on GaN are already in the market, mainly on small-size substrates of 6-inches. Manufacturers include International Rectifier, a U.S.-based power management company, and Fuji Electric in Japan, he noted.
Asked what IME's research focus is for GaN, Lo said the institute is looking to build capabilities in process technologies to scale GaN-on-Silicon to 8-inch substrates.
"IME is currently exploring the use of GaN in efficient, energy-saving devices such as power converters, whether it is AC to AC or DC to DC, with energy-efficient application such as [electronic] appliances and electric cars," the executive added.  
Telecoms equipment maker Huawei Technologies echoed both the Fujitsu research note and Lo's observations, saying GaN technology is "widely recognized" as a key technology for next-generation wireless base stations.
Huawei spokesperson, Lynn Zeng, told ZDNet Asia that the technology "significantly improves power amplifier efficiency in base stations", and research and development (R&D) efforts in this space is "commonplace" across the entire telecommunications industry.

Huawei denies involvement

Asked if the Chinese company was in partnership with IME to develop GaN technology, in a project Todd was reportedly spearheading, Zeng said: "IME approached Huawei on one occasion to cooperate with it in the GaN field, but we decided not to accept, and consequently do not have any cooperation with IME related to GaN."

"Huawei does not do military equipment or technology, nor do we discuss it with partners" - Huawei's Lynn Zeng

She added that Huawei's global R&D and sales efforts relate only to telecommunications solutions for civil and commercial use. "Huawei does not do military equipment or technology, nor do we discuss it with partners," she stated in her e-mail.

The company has been under the spotlight recently, after the United States identified Huawei as a cybersecurity threat. The European Union and the United Kingdom have also expressed similar concerns.  

The FT last Friday linked Todd's research work on GaN with his death, as it stated the American engineer was increasingly concerned his work for IME and an unknown Chinese partner company was compromising U.S. national security. The Chinese company was suspected to be Huawei as there was a file named after it, which was saved on the external hard disk found in Todd's apartment following his death.
The news agency then had Colin Humphreys, who is the director of research at the Cambridge University Centre for Gallium Nitride, review the "Huawei" project saved on the external hard disk. He said the content showed a plan for a GaN-based high-electron mobility transistor, which is an amplifier with commercial and military applications.
He told FT: "You can't say it is 100 percent for military use. There are many civilian uses. [But you] would be foolish not to think of military uses because there is a huge market for it."
Humphreys added the Chinese government has a substantial interest in commercial use of GaN as it subsidized the purchase of GaN-growth systems for the production of LEDs, which is part of an effort to reduce the country's electricity usage.
ZDNet Asia also contacted the Singapore Police Force (SPF) to find out if Todd had alerted officials to possible wrongdoings and initiate an investigation. The SPF said the engineer did not lodge a report.

It also pointed to the statement it issued on Sunday, which said it investigates all unnatural death cases thoroughly and no prior assumptions are made on the cause of the person's death.

The full statement can be seen below:

"The Police investigate all unnatural death cases thoroughly, working closely with the pathologist and other relevant experts, and no prior assumptions are made on the cause of death. Our procedures for investigating cases, particularly those involving death of persons, are strict and of high international standards. We have handled this case in the same way as other cases that Police have looked into.  
All crime scene locations which have the potential for recovery of evidence are handled with care and are protected from interference of any kind so as to preserve any trace evidence. The sites are secured by Police for the duration required for scene examination and evidence collection. The conditions and items found at the crime scene are carefully recorded in great detail, as well as conserved and removed for subsequent laboratory analysis.
The Financial Times article mentioned a hard disk which was purportedly recovered by Mr and Mrs Rick Todd from their son's residence. To ensure the investigations are as thorough as possible, we urge any person who has evidence in their possession that can assist in our investigation to share them with the Police. All relevant evidence gathered by Police will be tendered at the Coroner's Inquiry once the investigations are completed. The Coroner will independently determine the circumstances under which Mr Shane Todd came by his death taking into account the investigation findings and other evidence. During the open inquiry, the family of the deceased may question the witnesses and the relevant reports, including the pathologist report.  As investigations are ongoing, it is inappropriate for the Police to comment further on the case.
Since the death of Mr Shane Todd, the Police have engaged and assisted the family without impeding the objectivity of our investigation process. We will continue to do so. Police have also kept the American Embassy and FBI informed of this case."
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