Tuesday, June 25, 2013

Millennial Extremes 11: Gallium Nitride - Promises and Omens

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."
Silicon circuits cannot handle the heat generated by exponential computing demands imposed on them. The search is on to find materials that can allow us to push technology to ever greater extremes. It is a high stakes game, possibly one of the highest. The material that furnishes the substance of computer circuits sits at the heart of the Technological Revolution and at nano-levels crosses over into other areas of global concern: energy, space exploration, war.

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."
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