Tunable Doping Enabled by Dielectric Screening Layer in Carbon Nanotube Transistors

Abstract Doping is a crucial technique for achieving high‐performance carbon nanotube (CNT) metal‐oxide‐semiconductor field‐effect transistors (MOSFETs). However, excessive doping in the extension region can induce significant band‐to‐band tunneling (BTBT) leakage. In this work, the n‐type doping of CNTs is investigated using aluminum nitride (AlN) as the dopant material and present a tunable doping approach by incorporating various screening dielectric layers between CNTs and AlN. It is confirmed that the screening effect is the dominant factor governing doping strength and demonstrates tunable doping levels ranging from 0.26 to 0.89 nm⁻¹ by varying the screening materials and thickness. Furthermore, through the Wentzel–Kramers–Brillouin (WKB) approximation method, as the extension doping strength weakened from 0.75 to 0.45 nm⁻¹, the BTBT leakage current can be reduced from 19 to 1.2 nA/CNT, offering significant potential for future carbon‐based electronics.