Single event effects in carbon nanotube electronics

Recent studies on carbon nanotube (CNT) field-effect transistors (FETs) and integrated circuits (ICs) have shown their potential in radiation tolerance. This work thoroughly examined the SEE of the CNT devices. Using a pulse laser as the irradiation source, the CNT FETs and static random-access memory (SRAM) exhibited an excellent radiation tolerance with a laser threshold energy of 5 nJ/pulse for SEE.

A team of low dimensional material led by Maguang Zhu from Nanjing University in Suzhou, China recently researched the single event effect (SEE) of the CNT FETs and ICs to advance research in the field. CNT is increasingly recognized as a viable material for advanced IC applications due to its high saturation velocity, ultra-thin body, and high carrier mobility. Furthermore, owing to its nanoscale cross-sections and strong C-C bonds, which can reduce radiation damage, CNT has shown high radiation tolerance.

The team published their review in Nano Research on June 5, 2025.

“In this work, we thoroughly examined the SEE radiation tolerance of the CNT devices. Using the pulse laser as the irradiation source, we tested SEE of the local bottom gate CNT FETs and SRAM, and they exhibited an outstanding radiation tolerance of up to 5nJ/pulse for the SEEs (SET and SEU). In addition, we conducted a comparison of the SEE between the CNT-based devices and Si-based devices through the TCAD simulation. Owing to the nanoscale cross-sections and the special SEE mechanism in CNT FETs, the CNT FETs feature a much stronger SEE tolerance compared to the Si-based devices. These results indicate that CNT-based devices can be an excellent radiation-hard technology for the applications of outer space exploration.” said Maguang Zhu, corresponding author of the paper, assistant professor in the School of Integrated Circuit at Nanjing University.

CNT is a kind of special carbon nanotube with high aspect ratio and hollow tubular structure. The rice material can be seen as a two-dimensional graphene coiled along a certain direction, with different layers of graphene spinning. Benefitting from the ultrathin body, high carrier mobility, and high saturation velocity, CNT has been demonstrated to be an excellent channel to construct ultra-scaled FETs with high performance and low power dissipation.

The research team thoroughly examined the SEE of the CNT devices. Owing to the nanoscale cross-sections and the special SEE mechanism in CNT FETs, the CNT FETs exhibited an outstanding radiation tolerance of up to 5nJ/pulse for the SEEs.“Previous studies indicated that the SEE phenomenon in a transistor is governed by two correlated mechanisms: the collection of radiation-generated electron-hole pair generation, which is quantitatively related to the radiation-sensitive volume, and extra-charge-induced channel potential reduction, resulting in a drift current from drain to source. For the conventional Si transistors, SEE response is predominantly attributed to the first mechanism as these devices possess a huge sensitive channel volume. In contrast, the CNT FETs feature ultrathin channels and relatively small sensitive volumes, in CNT FETs the SEE is primarily dominated by the second mechanism.”said Maguang Zhu.

The authors used Technology computer-aided design (TCAD) simulations to explore the SEE of the CNT FETs. In CNT devices the SEE response primarily emerging from the channel’s potential drop, which is strongly influenced by the gate control efficiency. Therefore, improving the gate control capability, such as suppressing the trap density or decreasing the thickness of the gate dielectric, may effectively improve the SEE tolerance. By reducing the gate oxide/channel interface trap density from 10¹³ cm^-2 to 10¹² cm^-2, the SET peak current decreased from 3.88 mA to 3.03 mA. And scaling the thickness of gate dielectric from 50 nm to 8 nm reduced the peak current from 0.52 mA to 0.37 mA.

In addition, a comparative study of the CNT FET and the Si-based devices was conducted. In the simulations, the fully-depleted silicon on insulator (FDSOI) transistors featured a > 4x higher peak current than the CNT FET. And the Si nano-sheet FET (NSFET) featured a > 30x higher peak current together with a ~ 3x higher FWHM compared to the CNT FET. These results demonstrated that CNT devices have better SEE tolerance compared to the Si-based devices in ultra-scaled technology nodes, indicating that CNT devices can serve as an excellent radiation-hard technology in the post-Moore era.

Ruhai Liu, Yifu Sun from the School of Integrated Circuit at Nanjing University in Suzhou, China, and Rui Chen, from The State Key Laboratory of Space Weather, National Space Science Center at Chinese Academy of Sciences in Beijing, China are the Co-first authors. Maguang Zhu from the School of Integrated Circuit at Nanjing University in Suzhou, China, Peng Lu from the Institute of Microelectronics of the Chinese Academy of Sciences at Key Laboratory of Science and Technology on Silicon Devices in Beijing, China, and Zhiyong Zhang from the School of electronics at Peking University in Beijing, China are the corresponding authors.

This work was supported by the National Natural Science Foundation of China (Grant No. 62301247), the Fundamental Research Funds for the Central Universities (Grant No. 2024300427), the Natural Science Foundation of Jiangsu Province (Grant No. BK20230778) and the Key Research and Development Program of Jiangsu Province (Grant No. BK20232009), the Innovation Leading Talent Foundation of Suzhou (Grant No. ZXL2023164).

About Nano Research

Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.