At IBM’s Watson Research Center in upstate New York, some of the world’s best physicists, chemists, and nanoengineers are trying to create the first high-density, self-assembling carbon nanotube computer chip process. In much the same way that Jack Kilby at Texas Instruments discovered the monolithic VLSI process for making silicon chips in 1958, IBM desperately wants to find the process that enables the creation of carbon nanotube chips. In the next decade — or thereabouts; the goalposts keep shifting — silicon is expected to reach a miniaturization roadblock.
At some point, we simply won’t be able to make silicon transistors any smaller. When this happens, there will be a few materials jostling to fill the void, most notably silicon-germanium, galium arsenide, and various forms of carbon (nanotubes, nanowires, graphene). In theory, computer chips made from carbon nanotubes are massively desirable — they would be many times faster than silicon, use less power, and can scale down to just a couple of nanometers. In practice, working with carbon nanotubes — just like graphene — is proving to be rather difficult. It’s sometimes easy to forget that we have decades of experience and billions of R&D dollars plowed into silicon; expertise with new materials won’t come easy.