Carbon nanotube tip probes: stability and lateral resolution in scanning probe microscopy and application to surface science in semiconductors

In this paper we present results on the stability and lateral resolution ca pability of carbon nanotube (CNT) scanning probes as applied to atomic forc e microscopy (AFM). Surface topography images of ultra-thin films (2-5 nm t hickness) obtained with AFM are used to illustrate the lateral resolution c apability of single-walled carbon nanotube probes. Images of metal films pr epared by ion beam sputtering exhibit grain sizes ranging from greater than 10 nm to as small as similar to2 mn for gold and iridium. respectively. In addition, the imaging stability and lifetime of multi-walled carbon nanotu be scanning probes are studied on a relatively hard surface of silicon nitr ide (Si3N4). AFM images of the Si3N4 surface collected after more than 15 h of continuous scanning show no detectable degradation in lateral resolutio n. These results indicate the general feasibility of CNT tips and scanning probe microscopy for examining nanometre-scale surface features of deposite d metals as well as non-conductive thin films. AFM coupled with CNT tips of fers a simple and nondestructive technique for probing a variety of surface s, and has immense potential as a surface characterization tool in integrat ed circuit manufacture.