The Influence of Growth Method Towards Carbon Nanotube Field Effect Transistor Performance

Due to its exceptional electronic properties, single walled carbon nanotubes (SWCNTs) can be applied as the active channel of high-performance carbon nanotube field effect transistors (CNTFETs). The electronic properties of SWCNTs are known to be affected by its intrinsic properties, including electronic type, diameter and structural defects. Since tube defect is dependent of the growth method, it is shown that the latter can also influence the CNTFET device performance. Four SWCNT samples from different growth methods were sourced to fabricate CNTFETs. Raman analysis was carried out to quantify the tube defect level of SWCNTs by determining the G-peak to D-peak height ratio. Electrical measurement was carried out to assess the key device performance parameters that include on-off current ratio, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{I}_{\mathbf{ON}}/\boldsymbol{I}_{\mathbf{OFF},}$</tex> transconductance, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{g}_{\mathbf{m}}$</tex> , subthreshold slope, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{S}_{\mathbf{p}}$</tex> and field effect mobility, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu_{\mathbf{FE}}$</tex> . Correlation between the optical analysis and electrical measurement concludes that the SWCNT growth method does influence the CNTFET performance significantly.