Electromechanical Carbon Nanotube Switches for High-Frequency Applications

• Published in: Nano letters 2006-05, Vol.6 (5), p.942-947
• Main Authors: Kaul, Anupama B., Wong, Eric W., Epp, Larry, Hunt, Brian D.
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Electrochemistry; Electronics; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Micro- and nanoelectromechanical devices (mems/nems); Microscopy, Electron, Scanning; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Nanotubes, Carbon - chemistry; Nanotubes, Carbon - ultrastructure; Other topics in nanoscale materials and structures; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Theory and models of film growth
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl052552r

We describe the fabrication and characterization of a nanoelectromechanical (NEM) switch based on carbon nanotubes. Our NEM structure consists of single-walled nanotubes (SWNTs) suspended over shallow trenches in a SiO2 layer, with a Nb pull electrode beneath. The nanotube growth is done on-chip using a patterned Fe catalyst and a methane chemical vapor deposition (CVD) process at 850 °C. Electrical measurements of these devices show well-defined ON and OFF states as a dc bias up to a few volts is applied between the CNT and the Nb pull electrode. The CNT switches were measured to have speeds that are 3 orders of magnitude higher than MEMS-based electrostatically driven switches, with switching times down to a few nanoseconds, while at the same time requiring pull voltages less than 5 V.