Hunan Institute of Advanced Sensing and Information Technology Publishes Important Research Progress in Carbon-based Integrated Circuits on Science
Recently, Professor Zhang Zhiyong and Academician Peng Lianmao of Hunan Institute of Advanced Sensing and Information Technology made important progress in the research of carbon-based integrated circuits. On May 22, Science published online the research result with the title of “Aligned, high-density semiconducting carbon nanotube arrays for high-performance electronics" (Science, 368,6493,850 ～ 856). This work shows for the first time in the experiment the performance advantages of carbon tube devices and integrated circuits over traditional technologies; it has broken through the bottleneck that has hindered the development of carbon tube electronics for a long time; and, laid a foundation for the practical development of carbon-based integrated circuits. Ding Sujuan, one of the first batch of postgraduates enrolled by the institute and one of the authors of the research paper, has contributed a lot of characterization and testing work under the joint guidance of Dean Peng Lianmao, Executive Deputy Dean Zhang Zhiyong, and Distinguished Professor Jin Chuanhong.
As mainstream CMOS integrated circuits shrink to the sub-10 nm technology node, it becomes more and more important to adopt new structures or new materials to combat the short-channel effect in field-effect transistors and further improve the device’s energy utilization efficiency. Semiconductor carbon nanotubes have ultra-high electron and hole mobility, atomic-scale thickness and stable structure, and are ideal channel materials for building high-performance CMOS devices. Both theoretical calculations and experimental results show that the planar structure of carbon tube CMOS transistors can be reduced to 5nm gate length, and the silicon-based CMOS devices with the same gate length have 10 times of the comprehensive advantages in intrinsic performance-power consumption.
Academician Peng Lianmao and Professor Zhang Zhiyong led the research team to develop a new purification and self-assembly method, using multiple polymer dispersion and purification techniques to obtain ultra-high-purity carbon tube solution. Combined with the dimension-limiting self-alignment method, they prepared a carbon tube array with a density of 120 / μm, a semiconductor purity of 99.99995%, and a diameter distribution of 1.45 ± 0.23 nm on a 4-inch substrate. This met the needs of ultra-large-scale carbon tube integrated circuits and solved key bottleneck of the constraints on the actual performance of carbon tube transistors and integrated circuits. On this basis, field effect transistors and ring oscillator circuits were prepared in batches. The peak transconductance and saturation current of 100nm gate-length carbon tube transistors reached 0.9 mS / μm and 1.3 mA / μm (VDD = 1V), respectively. The subthreshold swing at room temperature reached amplitude of 90 mV / DEC. The batch production of fifth-order ring oscillator circuits reached a yield rate of more than 50%, with a maximum oscillation frequency of 8.06 GHz, far exceeding the disclosed nano-material-based circuits, and its performance surpassed the transistors of the same gate length silicon-based CMOS technology and circuits, showing the great advantages of carbon tube electronics.
The Hunan Institute of Advanced Sensing and Information Technology, supported by the Hunan Provincial People’s Government, is a new research and development platform jointly established by Beijng University and Xiangtan University in 2018. It aims to be a national innovation center and first-class technology industry promotion center for carbon-based nano electronic devices and new high-end sensors research and development. At present, the work of the institute has been in smooth progress. It has built the most advanced and national leading micro-nano device processing laboratory in central south China; recruited a group of high-end talents including academicians of the Chinese Academy of Sciences and National Excellent Youth program; and, enrolled more than 20 master and doctoral candidates. The institute has made a series of important progress in carbon-based gas sensor arrays, biomedical sensors, and flexible electronic devices, including this research result published online on Science this time. It has published more than 30 high-level research papers, and has been communicating with Huawei, BOE, Xuhai Opto-Electronic, CLP Holdings and other leading enterprises for industry-university-research cooperation, to bring relevant research results to the market as soon as possible.