Fabrication of ultrafine nanostructures with single-nanometre precision in a high-resolution transmission electron microscope

Abstract

Highly ordered ultrafine nanostructures (feature size <10 nm) have been successfully fabricated with single-nanometre precision using a convergent electron beam (CEB) in a high-resolution transmission electron microscope (HRTEM). This approach can be widely applied to inorganic solid-state materials including insulators, semiconductors and metals. The feature size can be precisely controlled by the probe size and the irradiation time. The formation mechanism of nanostructures fabricated by CEB has been discussed in terms of knock-on damage and the beam heating effect. On the basis of the experimental results of electron energy-loss spectroscopy (EELS), finite element thermal analysis reveals that the heating effect of the high-energy electron beam is negligible in inorganic solid-state materials, and the sculpting of nanostructures is predominated by the knock-on damage or ionization of high-energy electrons.

Structural Requirements for the Antiproliferative Activity of Pre‐mRNA Splicing Inhibitor FR901464

“…Additionally, in 2001, ion beam sculpting was reported as a novel way to make a single nanopore in Si 3 N 4 membranes with nanometer precision 23. Since 2001, the dynamics of nanopore fabrication has been well studied and continues to grow 82, 85, 89, 90. Nanopore fabrication techniques using an electron beam, ion beam, or a combination of these have been the most popular techniques pursued to date 23, 78, 89…”

Solid-State Nanopore Technologies for Nanopore-Based DNA Analysis

“…More recently, several groups have produced electron-beam drilled pores within this size range [17,37], usually as a starting point for one of the shrinking methods described above. Zhang et al achieved even higher resolution, drilling subnanometer diameter pores in ZnO [38]. They explored a wide range of materials, creating pores in thin samples (30-100 nm) of crystalline Si, Si 3 N 4 , Al 2 O 3 , AlN, polycrystalline Ni, Al, Au, and amorphous C. With their crystalline samples, convergent beam electron diffraction (CBED) proved useful to determine membrane thickness adjacent to the pores.…”

Fabrication of nanopores using electron beam

“…Although many methods (magnetron sputtering, chemical etching, ion beam induced sputtering, etc) were developed to fabricate nanopores, it is difficult to reduce the nanopore size to sub-5 nm. Nevertheless, electron beam irradiation inside a transmission electron beam (TEM) has become the most effective way to obtain such small pores [13][14][15][16][17][18][19]. Previous experiments [13][14][15] indicate that electron beam size is one of the limiting factor to ultimate pore size, and the beam size could be focused to several nanometer even sub-nanometer inside a TEM.…”

“…Nevertheless, electron beam irradiation inside a transmission electron beam (TEM) has become the most effective way to obtain such small pores [13][14][15][16][17][18][19]. Previous experiments [13][14][15] indicate that electron beam size is one of the limiting factor to ultimate pore size, and the beam size could be focused to several nanometer even sub-nanometer inside a TEM. On the other hand, nanopore size could be modulated by electron beam irradiation at optimized electron intensity to reduce the surface free energy and to reconstruct more stable nanostructure, which is possible to reduce the pore size to 5 nm, even closure [16][17][18][19].…”