Carbon Nanotube Field-Effect Transistors

Carbon nanotube field-effect transistors (CNFETs) are poised to revolutionize digital logic by combining speed and energy efficiency. Compared to IMEC's 2nm silicon nanosheet technology, the ultrathin body of carbon nanotubes, as small as 1 nm, ensures exceptional gate control, while their inherently high mobility—even at such thin dimensions—delivers superior charge transport. These unique properties enable CNFETs to achieve 1.8× higher current densities.

As a result, to achieve the same drive current, CNFETs require fewer nanosheet (Nsh) channels and operate at lower voltages. Additionally, longer extensions—which increase the space between the gate and contact—provide a significant capacitance advantage. The effective capacitance (C_eff), extracted from dynamic energy simulations at the ring oscillator level, demonstrates a capacitance advantage of up to 1.9×.

Thanks to their high current, lower capacitance, and reduced operating voltage, CNFETs offer up to a 7× improvement in energy-delay product (EDP), making them a compelling candidate for future high-performance, energy-efficient digital logic.

We are looking for new nanomaterials and nanotechnologies to optimize every component of CNFETs, including the contact, channel, gate stack, architecture, and doping, to deliver the promised gains. We have developed a new doping technique for CNFETs, which is also applicable to other low-dimensional materials such as 2D materials. With this new doping technique, we have successfully demonstrated iso-performance CNT NMOS and PMOS using solid-state dopant compatible with foundry processes. We will continue working on carbon nanotube-based digital circuits and aim to realize the lab-to-fab transition.