Carbon nanotube materials for future integrated circuit applications

Aligned carbon nanotubes (A-CNTs) have been demonstrated to be promising materials for constructing advanced complementary metal-oxide-semiconductor (CMOS) field-effect transistors (FETs) for future integrated circuits (ICs). However, the requirements of A-CNT materials from the perspective of IC applications, such as the distributions of length, alignment, diameter and density of CNTs, have not been explicitly researched or mentioned before. In this article, we review the progress on CNT electronics and electronic-grade materials and establish material criteria for A-CNTs applicable to advanced electronics according to the developing roadmap of CNT-based ICs. Specifically, electrical performance predictions for A-CNT CMOS FETs at various technology nodes are built based on a theoretical model and experimental results, and then, the criteria for ideal A-CNTs are outlined by evaluating the energy-delay product (EDP) advantage of CNT FETs over similar node commercial silicon (Si)-based CMOS transistors. The fine requirements for A-CNT materials are estimated for 90 nm, 22 nm, 7 nm, and 3 nm node CNT CMOS FETs, which present significant advantages in terms of energy efficiency over Si CMOS transistors. The criteria will guide the development of CNT materials for future ICs and provide a comprehensive assessment of the opportunities and challenges in CNT electronics.