Nanorobotic Assembly and Focused Ion Beam Processing of Nanotube-Enhanced AFM Probes

In this paper, a focused ion beam processing technique is presented that facilitates the modification of carbon nanotubes (CNTs) in terms of length, diameter, and orientation. The CNTs are mounted onto an atomic force microscope (AFM) probe by using a nanorobotic microgripper-based pick-and-place handling strategy. Such CNT-enhanced AFM probes are needed for metrology measurements of nanostructures with critical dimensions and high aspect ratios. The complete process of assembly and processing is realized inside a nanorobotic dual beam scanning electron microscope (SEM) and focused ion beam (FIB) machine. Note to Practitioners-This paper is motivated by the need of providing novel AFM probe tips for critical dimension metrology in nanooptical and nanoelectronic applications. In this area, the analysis of high-aspect ratio and sidewall structures is one of the most crucial challenges in improving and optimizing the current feature size and performance. For this purpose, this paper presents a nanorobotic system and strategy facilitating the assembly and processing of CNT-enhanced AFM probes. While the assembly process has already been shown to be fully automated, this paper focuses on postprocessing techniques for the assembled CNT tips by FIB-milling in order to adapt them to the specific application. The results clearly show a high reproducibility of the FIB processing so that future work will concentrate on automating this process as well to increase the possible fabrication throughput.