Selective growth of carbon nanotube on scanning probe tips by microwave plasma chemical vapor deposition

Abstract

We have selectively grown carbon nanotubes on the probe tip of an atomic force microscope by microwave plasma chemical vapor deposition. The catalyst domain was defined on the tip apex of an Si based scanning probe by local electric field induced oxidation of a TiN cap layer, under which the cobalt catalyst layer was predeposited on the probe surface. High resolution atomic force microscopy images of an SiO2 trench pattern are demonstrated using the carbon nanotube tip. The nanotube tip fabrication method is simple and compatible with existing thin film process technology.

Fabrication of Carbon Nanotube Tips for Scanning Tunneling Microscopy by Direct Growth Using the Microwave Plasma-Enhanced Chemical Vapor Deposition

“…In place, growth of CNT was observed only at the root of metal tip. This tendency is basically similar to that reported by Pan, et al [14] and Yoshimura, et al [15]. Since the ion flux at the tip apex is higher than that at the root due to different electric field concentration, Fe catalyst would be sputtered away preferentially from the tip apex by the ion bombardment.…”

“…The conductive CNT probes would be useful in a multiprobe microscope [9]. Several fabrication methods of CNT tips have previously been demonstrated, for example, manual attachment of a CNT to the tip apex using an acrylic adhesive [2], electron beam induced deposition (EBID) of amorphous carbon under scanning electron microscope (SEM) [10], and direct growth by a chemical vapor deposition (CVD) technique [11][12][13][14][15].…”

“…By using plasma CVD for the fabrication of CNT tip, the CNT aligned parallel to the tip axis is possible, because the direction of incident ion of carbon species can be controlled by an applied electric field. However, the growth of CNT on the tip apex of small radius is extremely difficult due to the damage of plasma [14,15]. Yoshimura, et al report successful fabrication of carbon nanostructures by reducing plasma damage [15].…”

Direct Fabrication of Carbon Nanotubes STM Tips by Liquid Catalyst‐Assisted Microwave Plasma‐Enhanced Chemical Vapor Deposition

“…It is demonstrated that the CNTs are suitable as tips of atomic force microscopy (AFM) [2][3][4] and scanning tunneling microscopy (STM) [5,6]. Numerous methods to make CNTs tips have been reported: manual attachment of CNTs to the tip apex using an acrylic adhesive [2], electron beam-induced deposition (EBID) of amorphous carbon under SEM [7], and direct growth by a chemical vapor deposition (CVD) technique [8][9][10][11][12]. The CVD technique is most preferred in terms of mass production in the commercial use.…”