Doping-Free Fabrication of Carbon Nanotube Based Ballistic CMOS Devices and Circuits

• Published in: Nano letters Vol. 7; no. 12; pp. 3603 - 3607
• Main Authors: Zhang, Zhiyong, Liang, Xuelei, Wang, Sheng, Yao, Kun, Hu, Youfan, Zhu, Yuzhen, Chen, Qing, Zhou, Weiwei, Li, Yan, Yao, Yagang, Zhang, Jin, Peng, Lian-Mao
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-12-2007
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Materials science; Molecular electronics, nanoelectronics; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Optoelectronic devices; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors; Patterning; Semiconductor materials; Semiconductor devices; Field effect transistors; Doping; Carbon nanotubes; Palladium; Photodetectors; Integrated circuits; Logic circuits; Complementary MOS technology; High k dielectric; Arrays; Nanostructured materials; Gates; Nanotechnology; Nanomaterial synthesis
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl0717107

We have fabricated ballistic n-type carbon nanotube (CNT)-based field-effect transistors (FETs) by contacting semiconducting single wall CNTs using Sc. Together with the demonstrated ballistic p-type CNT FETs using Pd contacts, our work closes the gap for doping-free fabrication of CNT-based ballistic complementary metal-oxide semiconductor (CMOS) devices and circuits. We demonstrated the feasibility of this doping-free CMOS technology by fabricating a simple CMOS inverter on a SiO2/Si substrate using the back-gate geometry, but in principle much more complicated CMOS circuits may be integrated on a CNT on any suitable insulator substrate using the top-gate geometry and high-κ dielectrics. This CNT-based CMOS technology only requires the patterning of arrays of parallel semiconducting CNTs with moderately narrow diameter range, for example, 1.6−2.4 nm, which is within the reach of current nanotechnology. This may lead to the integration of CNT-based CMOS devices with increasing complexity and possibly find its way into the computers brain:  the logic circuit.