Batch fabrication of carbon nanotubes at AFM probe tips and AFM imaging

Kazuhiko TAKAGAHARA, Yusuke TAKEI, Eiji IWASE, Kiyoshi MATSUMOTO, and Isao SHIMOYAMA
Graduate School of Information Science and Technology, The University of Tokyo, JAPAN

Purpose

Conventional AFM tips can be enhanced by attaching carbon nanotubes to their tips. Carbon nanotubes enhance tips’ toughness and horizonal resolution due to their strength and nanometer-scale diameters, respectively.

Method

Single wall carbon nanotubes were synthesized on an array of commercial silicon AFM tips using CVD. First, an oxidation layer was formed on the AFM tip. Second, the AFM tip was dipcoated in CNT-forming catalyst. Third, the array was put on a titanium jig where the AFM tips formed an electode with a counter silicon electrode. A high electric field was formed at the AFM tip (due to curvature). Then, argon gas plus ethanol were introduced to initate CNT growth.

Results

- Resonance Raman spectroscopy confirmed the formation of single-walled CNT of diameter ~1.2nm.

- Improved horizontal resolution was obeserved when passing the CNT-AFT tips over photoresist nanograting.