Carbon nanotube transistors with 60mV/decade switching and its capacitance measurement

Abstract

Recently, we have been able to approach the ultimate vertical scaling limit of carbon nanotube field effect transistors (FETs) and reliably achieve S ∼ 60 mV/decade at room temperature, by non-covalent functionalization of single walled carbon nonotubes (SWNTs) with ploy-T DNA molecules, which can impart functional groups of sufficient density and stability for uniform and conformai ALD of high-κ dielectrics (HfO2) with thickness down to 3 nm on SWNTs. Moreover, the small top gate stack capacitance (∼300aF/ μ m) of the SWNT FET has been successfully measured directly, using a special technique. The mobility of the SWNT FETs at room temperature is also extracted by the capacitance measured directly.