Complementary Transistors Based on Aligned Semiconducting Carbon Nanotube Arrays

High-density semiconducting aligned carbon nanotube (A-CNT) arrays have been demonstrated with wafer-scale preparation of materials and have shown high performance in P-type field-effect transistors (FETs) and great potential for applications in future digital integrated circuits (ICs). However, high-performance N-type FETs (N-FETs) have not yet been implemented with A-CNTs, making development of complementary metal-oxide–semiconductor (CMOS) technology, a necessary component for modern digital ICs, impossible. In this work, we reveal the mechanism hindering the realization of A-CNT N-FETs contacted by low-work-function metals and develop corresponding solutions to promote the performance of N-FETs to that of P-type FETs (P-FETs). The fabricated scandium (Sc)-contacted A-CNT N-FET with a 100 nm gate length exhibits an on-state current (Ion) of 800 μA/μm and a peak transconductance (gm) of 250 μS/μm, representing the highest performance of CNT-based N-FETs to date. Moreover, CMOS technology has been developed to realize N- and P-FETs with symmetric high performance based on A-CNTs. The fabricated A-CNT CMOS FETs show electron and hole mobilities of 325 and 241 cm2 V–1 s–1, respectively, which are slightly higher than the corresponding values of Si CMOS transistors. Our scalable fabrication of A-CNT CMOS FETs with comparable electronic performance to Si CMOS will promote the application of CNT-based electronics in digital ICs.