Suppression of leakage current in carbon nanotube field-effect transistors

• 作 者: Lin Xu Chenguang Qiu Lian-mao Peng Zhiyong Zhang
• 机 构: Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics,Peking Uni
• 出 处: 纳米研究（英文版）
• 发表日期: 2021年4期
• 关键词: carbon nanotube field-effect transistor leakage current TCAD simulation narrow-b

Carbon nanotube field-effect transistor (CNT FET) has been considered as a promising candidate for future high-performance and low-power integrated circuits (ICs) applications owing to its ballistic transport and excellent immunity to short channel effects (SCEs).Still,it easily suffers from the ambipolar property,and severe leakage current at off-state originated from gate-induced drain leakage (GIDL) in CNT FETs with small bandgap.Although some modifications on device structure have been experimentally demonstrated to suppress the leakage current in CNT FETs,there is still a lack of the structure with excellent scalability,which will hamper the development of CNT FETs toward a competitive technology node.Here,we explore how the device geometry design affects the leakage current in CNT FETs,and then propose the possible device structures to suppress off-state current and check their availability through the two-dimensional (2D) TCAD simulations.Among all the proposed structures,the L-shaped-spacer CNT FET exhibits significantly suppressed leakage current and excellent scalapility down to sub-50 nm with a simple self-aligned gate process.According to the simulation results,the 50 nm gate-length L-shaped-spacer CNT FET exhibits an off-state current as low as approximately 1 nA/μm and an on-current as high as about 2.1 mA/μm at a supply voltage of-1 V and then can be extended as a universal device structure to suppress leakage current for all the narrow-bandgap semiconductors based FETs.