IBM researchers believe to have found a way to overcome the physical limitations to shrink silicon in future computer chips. The company suggests that carbon nanotubes are key to smaller transistors as the material may be able to replace silicon at some point.
According to the company, it was able to produce "10,000 working transistors made of nano-sized tubes of carbon" and place them "precisely" on a single chip using "standard semiconductor processes". The placement density was one billion carbon nanotubes per square centimeter. Of course, 10,000 transistors are a far cry from the more than 1 billion transistors that are placed on today's CPUs. The precision rate of 99.8 percent appears to be close to the required 99.999 percent to achieve 1 billion transistors, but those extra 0.199 percent are more difficult to achieve than the previous 99.8 percent.
Nevertheless, IBM's announcement is remarkable and the company states that there is reason to believe that carbon nanotube transistors are likely to "replace and outperform silicon technology". In its research, IBM said it was able to position the carbon transistors by creating a circuit pattern on a substrate using a chemically-modified hafnium oxide (HfO2) and the rest of silicon oxide (SiO2). The added carbon nanotubes attached themselves to the HfO2via a "chemical bond", IBM said.
Carbon transistors are nowhere near commercial production, but IBM clearly sees the technology as a viable approach to build transistors that are "a few tens of atoms across". The company said that the material itself is also more attractive than silicon as electrons can move easier in carbon transistors than in silicon-based devices, which would result in faster chips.