Computer-aided design and growth of single-walled carbon nanotubes on 4 in. wafers for electronic device applications

We have employed computer-aided furnace design and process simulation to optimize the conditions under which single-walled carbon nanotubes (SWCNTs) may be grown in high yields on 4 in. wafers for electronic device applications. Hydrokinetic simulations were performed to obtain optimized furnace structures and process conditions in terms of gas flow, temperature, and gas speed. Shower head structures and a flow isolation barrier were installed in an experimental 6 in. furnace, as suggested by the hydrokinetic simulations. To ensure clean surfaces and uniform catalyst islands, catalyst patterns were lifted off using Au films or polydimethylsiloxane. Photolithography was used to fabricate field-effect transistors with SWCNTs grown on 4 in. wafer substrates. The total yield of the nanotube devices increased from 30.5% to 96.4% after optimization.