Integration of suspended carbon nanotube arrays into electronic devices and electromechanical systems

Abstract

A synthetic strategy is devised for reliable integration of long suspended single-walled carbon nanotubes into electrically addressable devices. The method involves patterned growth of nanotubes to bridge predefined molybdenum electrodes, and is versatile in yielding various microstructures comprised of suspended nanotubes that are electrically wired up. The approach affords single-walled nanotube devices without any postgrowth processing, and will find applications in scalable nanotube transistors (mobility up to 10 000 cm2/V s) and nanoelectromechanical systems based on nanowires.

Suspended Carbon Nanotube Quantum Wires with Two Gates

“…We succeeded in using refractory metals W and Pt/W (W as adhesive layer for Pt) as preformed electrodes and found that the typical resistance of our individual suspended SWNT devices was in the range of 10 -50 kΩ ( Figure 2 to 4). The contact resistance appeared higher than devices with nanotubes lying on substrates with Pd top-contacts [7,14] , but lower compared to other suspended SWNT devices including those with preformed Mo electrodes [4] or top-contacted Au electrodes [3] .…”

“…[1][2][3][4][5][6] Here, we report a reliable method for the fabrication of suspended SWNT devices with improved metalnanotube contacts and a useful double-gate design. These devices have led to the revelation of interesting electrical transport properties of nanotubes that are distinct from those pinned on substrates.…”

“…Chemical vapor deposition (CVD) was then used to grow SWNTs to bridge the electrode pairs on the wafer chip. [4,5] Low yield growth conditions were used (800 -825 °C) to afford mostly single tubes bridging the S/D pairs, as confirmed by scanning electron microscope (SEM) after electrical measurements of the devices. The results presented here were all obtained from individual suspended SWNT devices.…”

“…[4] Mo was chosen as the S/D electrode material due to its compatibility with SWNT growth and the ability of dry-etching of Mo for electrode patterning. In the current work, our fabrication process does not involve dryetching of metal and thus allows a wider choice of refractory metals.…”

Parallel arrays of individually addressable single-walled carbon nanotube field-effect transistors

“…Some recent developments toward an industrially favorable SWNT transistor fabrication process include prepatterned catalysts where SWNTs selectively grow at the device sites, [20][21][22][23][24] and dispersing SWNTs over a surface in order to produce an entangled network. 25,26 In this paper, we report a three-step procedure that yields individually addressable arrays of high-throughput SWNT FETs.…”