Extreme measures

THERE have been false warnings aplenty, but this time it looks real—or, at least, more real than at any time before. The fact is that silicon chips, as the world knows them, are reaching their limits. The present form of optical-projection lithography, which uses light to print circuit patterns on slivers of silicon, will soon hit the buffers. The wavelength of the light it uses means it is unable to print lines narrower than 0.1 micron (ie, one tenth of a millionth of a metre). Small as it may sound, that will still be too wide to fit the number of circuits on a chip that the semiconductor industry needs to keep up, as it has done for decades, with Moore's Law.