Ifs, buts and maybes

But as feature sizes shrank from many microns to almost single figure nanometres, wafers grew in diameter, driven by the economics of semiconductor production. Leading edge semiconductors are now made on 300mm wafers and Intel, Samsung and foundry giant TSMC are looking to move to 450mm wafers. The question of whether to use 300 or 450mm wafers is relatively short term; there remains the longer term technical challenge of meeting the scaling requirements of Moore's Law. The move to each new process node involves huge technical complexity and investment. Together, these challenges are concentrating the best minds in the industry. Alongside wafer diameter and feature size is the question of for how much longer silicon can be used; by general agreement, it will not scale for much longer. That only gives a few years to find a substitute – or to rewrite the laws of physics. There has been a lot of excitement recently about the potential of graphene to take over as the material of choice. What if a similar material could be found which is silicon based? Step forward silicene. Postulated a few years ago, the material has now been created in Japan and appears to be very similar to graphene in that it is a single atom thick layer of hexagonally linked silicon atoms. If silicene behaves in the same way as graphene and can be made as readily, then it might be the material that takes the industry forward. But it's a very big if.