High-performance n-type carbon nanotube field-effect transistors with estimated sub-10-ps gate delay

High-performance top-gated n-type single-walled carbon nanotube (CNT) field-effect transistors (FETs) have been fabricated using scandium contacts and HfO2 gate oxide and are benchmarked against the state-of-the-art n-type Si metal-oxide semiconductor FETs. Two key device metrics, the intrinsic gate-delay (CV∕I) and energy-delay product (CV∕I⋅CV2) per unit width, of the n-type CNT FETs are found to show significant improvement over the Si devices. In particular, the gate-delay time is estimated to be 2.1ps for an n-type CNT FET which is based on a CNT with a diameter of 1.1nm and a channel length of 220nm.