Intel has warned investors that following Moore's Law is getting increasingly difficult, as it admits to the first blip on the roadmap for the past several generations.

Moore's Law, named for Intel co-founder Gordon Moore, is the observation that the number of transistors found in complex integrated circuits like microprocessors doubles roughly every eighteen months - leading to a proportional increase in performance. While originally couched as a historical observation, Moore's rule has become a true law for the semiconductor industry which seeks to meet or exceed its expectations - and, generally, succeeds in doing so.

There are problems on the horizon, however. Doubling the number of transistors on a given integrated circuit typically requires halving the size of said transistors - otherwise we'd all be using CPUs the size of our houses by now. In lithography - the means by which the design of the processor is shrunk and applied to the semiconductor itself - this is known as the process node, with Intel's next-generation chips targeting a 14nm node.

As the size of the transistors themselves decreases, so does the size of everything else. There's a lower limit to how many times the process node can shrink: silicon, the material typically used for modern semiconductors, suffers from current leakage when the sizes involved are small enough - meaning components begin to interfere with their neighbours, turning what should be neatly-ordered data into gibberish. The lithographic machines themselves also struggle, needing ever-smaller wavelengths of light to etch their patterns onto the substrate.

Traditionally, Intel has met these challenges head-on and in doing so continued with its adherence to Moore's Law. At its most recent investor's day, however, the company revealed a slide that showed its struggles with getting the 14nm process right. These struggles, which caused higher than expected defect rates in the chips, are no surprise given that they are direction responsible for the 14nm Broadwell being delayed to 2014, but to hear Intel talk candidly on the subject is rare indeed.

'It’s the first time [we've had these troubles] in quite a number of generations,' Intel's William Holt told the Wall Street Journal at the invitation-only investor's day. 'It’s just getting really hard. [The problem is] just getting the size down. As hard as it is, it’s going to be just as hard for everybody else,' Holt added, reassuring investors that the problems aren't exclusive to the company.

An end to Moore's Law could spell trouble for the company. Traditionally, it's been that doubling in performance that has kept its customers upgrading year after year - and each process node shrink comes with a corresponding decrease in base manufacturing costs which helps offset the research and development needed in order to reach a given node. 'I’m not about to start predicting the end [to Moore's Law],' Holt told the paper, 'since anybody who has tried has been wrong.'

The issues surrounding a continuation of Moore's Law has led to several potential solutions over the past decade, from silicon oxide chips and nanowire grids to carbon nanotube transistors and purely optical computing. Few, however, are ready for mass production just yet.


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