Methods of creating and observing atomically reconstructed vertical Si{100}, {110}, and {111} side-surfaces

Abstract

We demonstrated the creation of atomically ordered side-surfaces and examined the perfection of the side-surface structures. Atomically reconstructed Si{100}, {110}, and {111} side-surfaces, which are perpendicular to planar surfaces, were first realized on three-dimensionally patterned Si substrates. The 2 × 1, 16 × 2, and 7 × 7 diffraction spots from the side-surfaces were confirmed by reflection high-energy electron diffraction. Epitaxial ultrathin metal and metal silicide films with an atomically matched lateral interface were grown on the side-surfaces. Methods of creating and observing well-defined surfaces enable the epitaxial growth of an arbitrary geometry, which becomes a key technique for nanoconstruction in three-dimensional space.

Creation and Evaluation of Atomically Ordered Side- and Facet-Surface Structures of Three-Dimensional Silicon Nano-Architectures

“…Ewald sphere in 3D RSM, for 3D crystal. 3D fabricated materials, the authors have demonstrated that not only substrate surfaces but also surfaces inclined from or perpendicular to a substrate plane exhibit atomically ordered structures where surface spots elongated along directions inclined from or perpendicular to the substrate normal direction appear in RHEED patterns ( Figure 5(b)) [6,7,9]. We emphasize that a simple surface property of 3D fabricated materials, that is, a surface direction, can be confirmed by the elongation of surface spots.…”

“…The process parameters were an ICP source power of 300 W, a bias power of 10 W, and a working pressure of 4 Pa. Mixture gases of 10 sccm SF 6 , 5 sccm O 2 , and 200 sccm Ar were used in the etching cycle, and 40 sccm C 4 F 8 , 5 sccm O 2 , and 200 sccm Ar were used in the passivation process [6][7][8][9]. Depending on dry RIE conditions, various curved structures from trapezoid to triangle shapes were obtained.…”

“…A 100 fg sample was dipped in 25 wt% tetramethylammonium hydroxide (TMAH) at 70°C for 3 min. A 110 fg sample was etched in 25 wt% TMAH with 0.1 vol% surfactant (iso-octylphenoxy polyethoxyethanol) at 70°C for 1 min [7]. Then, the sample was rinsed with pure water, dried by blowing with N 2 , and introduced into an ultra-high vacuum (UHV) chamber.…”

“…Low-energy electron diffraction (LEED) is also a conventional and nondestructive surface observation technique [5]. To apply these techniques to 3D structured samples with various oriented surfaces, instead of 2D planar samples, an appropriate alignment of the incident electron beam considering the configuration in 3D space is indispensable [6][7][8][9].…”

Atomically Architected Silicon Pyramid Single-Crystalline Structure Supporting Epitaxial Material Growth and Characteristic Magnetism

“…To overcome the remaining difficulties, we have proposed and demonstrated the creation of well-defined 3D structures by the combination of dry and wet etching processes, and the growth of epitaxial films on the side and facet surfaces of atomically constructed 3D Si templates. ,− The key advantage is a complete shift of the material growth direction from the normal c -axis on a 2D planar substrate toward flexible omnidirectional axes on a 3D patterned substrate with arbitrarily oriented planes. Reconstructed 3D Si surfaces support the epitaxial growth of target materials without misalignment or deformation, similar to the growth of thin films on 2D planar surfaces. ,,, …”