IBM claims to have made a breakthrough in using carbon nanotubes to fabricate chips.
IBM has spent years researching carbon nanotubes to replace silicon as the primary material for building chips. Now the firm has claimed to have made a breakthrough by precisely placing and testing more than 10,000 transistors made from carbon nanotubes using current semiconductor manufacturing processes.
According to IBM, its researchers developed a method of using ion-exchange chemistry drive the precise placement of transistors made using carbon nanotubes. The firm claims its technology yields a two orders of magnitude increase in density over previous technology to achieve a density of one billion transistors per square centimetre.
IBM provided some details about the process, saying, "The process starts with carbon nanotubes mixed with a surfactant, a kind of soap that makes them soluble in water. A substrate is comprised of two oxides with trenches made of chemically-modified hafnium oxide (HfO2) and the rest of silicon oxide (SiO2). The substrate gets immersed in the carbon nanotube solution and the nanotubes attach via a chemical bond to the HfO2 regions while the rest of the surface remains clean."
Not only was IBM able to place more than 10,000 transistors on a single chip, it claimed the ability to test them with existing high volume characterisation tools, which is an important aspect in making sure the technology is usable. The firm didn't say when it will be able to place 100,000 or more transistors on a single chip, but Big Blue seems to be making good progress as the industry looks ahead to reaching the circuit density limits of silicon based semiconductor chip technology. µ