Nanofabrication by advanced electron microscopy using intense and focused beam^∗

Abstract

The nanogrowth and nanofabrication of solid substances using an intense and focused electron beam are reviewed in terms of the application of scanning and transmission electron microscopy (SEM, TEM and STEM) to control the size, position and structure of nanomaterials. The first example discussed is the growth of freestanding nanotrees on insulator substrates by TEM. The growth process of the nanotrees was observed in situ and analyzed by high-resolution TEM (HRTEM) and was mainly controlled by the intensity of the electron beam. The second example is position-and size-controlled nanofabrication by STEM using a focused electron beam. The diameters of the nanostructures grown ranged from 4 to 20 nm depending on the size of the electron beam. Magnetic nanostructures were also obtained using an iron-containing precursor gas, Fe(CO) 5 . The freestanding iron nanoantennas were examined by electron holography. The magnetic field was observed to leak from the nanostructure body which appeared to act as a 'nanomagnet'. The third example described is the effect of a vacuum on the size and growth process of fabricated nanodots containing W in an ultrahigh-vacuum field-emission TEM (UHV-FE-TEM). The size of the dots can be controlled by changing the dose of electrons and the partial pressure of the precursor. The smallest particle size obtained was about 1.5 nm in diameter, which is the smallest size reported using this method. Finally, the importance of a smaller probe and a higher electron-beam current with atomic resolution is emphasized and an attempt to develop an ultrahigh-vacuum spherical aberration corrected STEM (Cs-corrected STEM) at NIMS is reported.

Charging effects during focused electron beam induced deposition of silicon oxide

“…[1][2][3][4][5] FEBID is typically done with a scanning electron microscope or dual beam instrument, but can be done in a transmission electron microscope (TEM) as well. [1][2][3][4][5] FEBID is typically done with a scanning electron microscope or dual beam instrument, but can be done in a transmission electron microscope (TEM) as well.…”

Decomposition of Fe5C2catalyst particles in carbon nanofibers during TEM observation

“…High-energy (160 keV) electrons passing through the sample collide with and damage the crystal lattice and displace the atoms of the catalyst particle and the nanofiber, generating point defects [18,19]. Moreover, these high-energy electrons generate low-energy secondary electrons, which may also play a role in the decay of the catalyst particle [20,21].…”

Nanowire Joining Methods

“…The high spatial accuracy makes it promising for building structures in nanoscale. The adsorption of high energy electron/ion beam by the substrate causes the re-emit secondary electrons with a wide range of energies to decompose gaseous precursor molecules, leading to the deposition of non-volatile fragments onto the nearby area [83][84][85].…”