Local Growth of Carbon Nanotubes with a Simple Mask CVD Method on 3-D substrates

Carbon nanotubes (CNTs) are potentially useful for developing functional nanodevices such as thermal probes, flow sensor arrays, and AFM probes. Controlling the growth position of CNTs grown by chemical vapor deposition (CVD) is crucial to fabrication of these nanodevices. We propose an easy, non-lithographic process of making CNT sensor probes using CVD. Growth positions of CNTs were precisely controlled by depositing a patterned barrier layer above the catalyst layer. Then, the CNTs were grown from the exposed catalyst layer using CVD. This method is easily applied to assembling bridged CNTs. We used focused ion beam etching to remove the barrier layer and expose the catalyst membrane. Using this method, we made a bridge of CNTs at the tip of a Si edge. This bridge is used to fabricate several nanoprobes for local sensing