Investigation and Improvement of the Bias Temperature Instability in Carbon Nanotube Transistors

Abstract

Carbon nanotube (CNT) is widely regarded as a promising candidate for constructing sub-10 nm field-effect transistors (FETs). However, limited attention is carried out on the reliability of CNT FETs, which is critical for practical application. In this work, the bias temperature instability (BTI) effect in top-gate CNT FETs is thoroughly investigated under a wide range of environment temperatures from 200 to 400 K for the first time. Notably, the threshold voltage (V_th) shifts induced by BTI are measured down to 0.38 V, which is ≈2–3 times smaller than those reported in previous studies. In addition, by optimizing the device fabrication process, the reliability of the BTI effects in CNT FETs can be further improved. The optimized CNT FET exhibits a Normalized BTI shift down to ≈0.10 V/(MV cm⁻¹), which represents the most reliable top-gate nano-devices to date.