Structural and electrical characterization of carbon nanotube field-effect transistors fabricated by novel self-aligned growth method

In this work, we report on the fabrication of carbon nanotube field-effect transistors (CNTFETs) using a low-cost process based on chemical vapor deposition (CVD) growth of carbon nanotubes (CNTs). The CNT growth occurs on the whole wafer surface and is assisted by a sacrificial Ni/Al catalyst. The process contains neither complicated manipulations of the SWNTs nor multi-step lithography, avoiding the risk of misalignment. Each step of the fabrication is compatible with the traditional CMOS technology. The fabricated structures are unipolar CNTFETs working like P-MOSFETs with on/off ratios up to 3 times 10
⁶
. We also report on the use of atomic force microscopy and its conductive extension to monitor the process and to provide structural and electrical information at the nanoscale.