Single Wall Carbon Nanotube Cantilever : Fabrication and Application

A single wall carbon nanotube (SWNT) has an extremely small diameter of 1∼2 nm and a high aspect ratio. For the use of the SWNT as an atomic force microscopy (AFM) cantilever, the SWNT was grown directly onto the top of the conventional silicon (Si) AFM cantilever using chemical vapor deposition (CVD) at 900oC in flowing CH4 gas. The length of the SWNT was hardly controlled in the growing process. Therefore, we cut the SWNT and adjusted its length at the top of the cantilever by bending and by applying the bias between the cantilever and the conductive substrate with monitoring the force curve and the vibration amplitude of the cantilever. The resolution of AFM using the optimized SWNT cantilever was compared with the one using conventional Si cantilever by observing the Au surface and TiOx lines fabricated utilizing the AFM nano-oxidation process. The radius of the SWNT cantilever was estimated by observing the width of the DNA in air.