Microchip miniaturisation barrier could be broken by nanotechnology
10 July 2006
A project that could remove the electrical wiring in
microchips, allowing denser circuitry, could result in computers with 500
times the power of present day technology. The University of Bath is to lead
an international £555,000 three-year project to develop the wireless silicon
As microchip circuits are made smaller to increase processing
power they approach a limit imposed by the need to use electric wiring,
which weakens signals sent between computer components at high speed.
Wireless systems are in widespread use in mobile phones, Bluetooth gadgets,
Wi-fi computers etc, but the electronics that create and use wireless
signals are too large to be used within individual microchips successfully.
The research project, which involves four universities in the UK and a
university and research centre in Belgium and France, will look at ways of
producing microwave energy on a small scale by firing electrons into
magnetic fields produced in semi-conductors that are only a few atoms wide
and are layered with magnets.
The process, called inverse electron spin
resonance, uses the magnetic field to deflect electrons and to modify their
magnetic direction. This creates oscillations of the electrons which makes
them produce microwave energy. This can then be used to broadcast electric
signals in free space without the weakening caused by wires.
possibility of using the special semi-conductors in this way was first
pointed out by Dr Alain Nogaret, of the University of Bath’s Department of
Physics, in an important scientific paper in 2005 (Electrically induced
Raman Emission from planar spin oscillator, in Physical Review Letters). The
latest research is the first attempt to turn theory into practice.
work could be very important for the creation of faster, more powerful
computers,” said Dr Nogaret. “We can only go so far in getting more power
from silicon chips by shrinking their components — conventional technology
is already reaching the physical limits of materials it uses, such as copper
wiring, and its evolution will come to a halt.
“But if this research is
successful, it could make computers with wireless semi-conductors a
possibility within five or ten years of the end of the project. Then
computers could be made anything from 200 to 500 times quicker and still be
the same size.
“This research may also improve the accuracy and speed of
medical diagnostics by gathering data from health monitoring sensors. The
microwave emitters are small enough to be integrated on portable biological
sensors which feed information out on faulty biological processes.
research is not only practical, but beautiful in its theoretical simplicity,
which is one of the big attractions for the physicists working on it.”
project is the only one which aims to create wireless emitters and receivers
that fit on semi-conductor wafers, where individual devices are one ten
thousandth of a millimetre in size.
It will also allow the creation of
integrated circuits which will still continue to work properly even if some
of its connections fail —the system can be programmed to reroute itself so
that it can continue working. At present a failure in a connecting wire can
put an integrated circuit out of action.
In the manufacture of today’s
integrated circuits there is no room for error, and so manufacturers must
spend large amounts of money to build dust-free clean rooms. The advantage
of the new more flexible system is that only 95% or so of the electronic
components would need to work for the chip to work properly. Such chips
would be many times cheaper to produce.
Dr Nogaret is working with
colleagues Professor Simon Bending and Professor John Davies in the
University’s £2m laboratory dedicated to nanotechnology.
receives £463,000 for the project, which begins in October. The University
of Nottingham receives £65,000, and the University of Leeds £27,000, all
from the Engineering and Physical Sciences Research Council. The University
of St Andrews in Scotland, and the University of Antwerp, Belgium, will also
take part, as will the Centre National de la Recherche Scientifique in