Advancement in fabrication of carbon nanotube tip for atomic force microscope using multi-axis nanomanipulator in scanning electron microscope

Abstract

We have constructed a new nanomanipulator (NM) in a field emission scanning electron microscope (FE-SEM) to fabricate carbon nanotube (CNT) tip to precisely adjust the length and attachment angle of CNT onto the mother atomic force microscope (AFM) tip. The new NM is composed of 2 modules, each of which has the degree of freedom of three-dimensional rectilinear motion x, y and z and one-dimensional rotational motion θ. The NM is mounted on the stage of a FE-SEM. With the system of 14 axes in total which includes 5 axes of FE-SEM and 9 axes of nano-actuators, it was possible to see CNT tip from both rear and side view about the mother tip. With the help of new NM, the attachment angle error could be reduced down to 0º as seen from both the side and the rear view, as well as, the length of the CNT could be adjusted with the precision using electron beam induced etching. For the proper attachment of CNT on the mother tip surface, the side of the mother tip was milled with focused ion beam. In addition, electron beam induced deposition was used to strengthen the adhesion between CNT and the mother tip. In order to check the structural integrity of fabricated CNT, transmission electron microscope image was taken which showed the fine cutting of CNT and the clean surface as well. Finally, the performance of the fabricated CNT tip was demonstrated by imaging 1-D grating and DNA samples with atomic force microscope in tapping mode.

Establishing Ohmic Contact of a Radial Compressed CNT Bundle with High Work Function Metal

“…In this paper, the hybrid AFM–SEM instrument was achieved by mounting the whole AFM on the sample stage inside an SEM vacuum chamber, or by inserting an AFM probe (tungsten probe) into the gripper of an SEM-based manipulator as the end-effector. , Hence, the hybrid AFM–SEM instrument was employed not only for robotic nanomanipulation − but also for obtaining the three-dimensional AFM images of sample contour . Through this hybrid AFM–SEM instrument, the ohmic contact was established between the multiwalled CNT (MWCNT) bundle and high work function metal Pt and Au.…”