Self-aligned double-gate suspended-body single-walled carbon nanotube field-effect-transistors

Self-aligned suspended-body single-walled carbon nanotube field-effect-transistors (SWCNT FETs) have been demonstrated with efficient and independent electrostatic control by two laterally placed independent gates spaced less than 100 nm away from the CNT channel. The operation of the suspended-body SWCNTFETs, in double-gate (DG) mode and single-gate (SG) mode, is analyzed in detail. Strong interface coupling of the double gates and tuning of the second independent gate (linear threshold voltage variation, constant subthreshold swing), are typical effects in these suspended-body SWCNTFETs. The comparison of SG and DG operations demonstrates the superiority of DG SWCNTFETs: remarkably improved subthreshold slope (from 130 mV/decade to 86 mV/decade) and transconductance (higher than four times the value in SG SWCNTFETs). The experimental data and the difference between SG and DG modes are explained. The double-gate suspended-body CNTFETs hold promise for bottom-up fabrication of resonant nano-electro-mechanical-systems (NEMS) devices, such as tunable/switchable resonators for sensing and radio-frequency (RF) applications.