Beyond silicon: the future of the CPU

The silicon processor needs a successor, says PC Plus

Printed electronics, as this science has come to be known, uses techniques that are more familiar to inkjet or laser printers than hi-tech chip manufacturers, as all the process really consists of is printing your circuits onto a flexible material. What is now familiar as a screen technology could soon become the basis for a future generation of microprocessors.

Next-generation processors

The commercial application of plastic printed circuits is already being realised. Plastic Logic is gearing up to produce sheets of semiconductor that can be used in a wide variety of applications.

First off, the production line in Dresden, Germany will produce A4-sized plastic sheets of polyethylene terephthalate substrate, the same material used to make drinks bottles. Manufacturing these new circuits also doesn't need complex plant and machinery, toxic chemicals or the high temperatures and pressures that traditional silicon-based chips require.

It's early days: the Plastic Logic plant will be fabricating to five to 10 micrometres scale, whereas today's silicon processor plants use nanometre scales.

Over time though, fabrication will improve as techniques are refined: Plastic Logic's R&D is already prototyping 60nm circuits. The technology could reduce the cost of devices by up to 90 per cent and herald a new age of consumer electronics. The first use of this new technology is likely to be in hands-on devices such as PDAs, mobile phones, eBook readers and ultra-portable PCs.

Chasing Moore's Law

How we build the next generation of microprocessors is evolving rapidly. There's still plenty of mileage in good old silicon. New fabrication techniques such as immersion lithography are coming online. However, eventually, silicon will have to be abandoned, and there are plenty of pretenders to its throne.

It's likely we'll see new compounds and alloys developed that can be a direct replacement for the silicon dielectric as we understand it today. But with nano science also developing rapidly, integrated circuit manufacture towards the middle of this century will have changed out of all recognition and consigned silicon to the world's science and technology museums.

This article has been adapted from an article published in PC Plus 262 (Dec 2007) and written by David Howell.

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