Two‐Dimensional Self‐Organization of an Ordered Au Silicide Nanowire Network on a Si(110)‐16 × 2 Surface

Abstract

A well-ordered two-dimensional (2D) network consisting of two crossed Au silicide nanowire (NW) arrays is self-organized on a Si(110)-16 x 2 surface by the direct-current heating of approximately 1.5 monolayers of Au on the surface at 1100 K. Such a highly regular crossbar nanomesh exhibits both a perfect long-range spatial order and a high integration density over a mesoscopic area, and these two self-ordering crossed arrays of parallel-aligned NWs have distinctly different sizes and conductivities. NWs are fabricated with widths and pitches as small as approximately 2 and approximately 5 nm, respectively. The difference in the conductivities of two crossed-NW arrays opens up the possibility for their utilization in nanodevices of crossbar architecture. Scanning tunneling microscopy/spectroscopy studies show that the 2D self-organization of this perfect Au silicide nanomesh can be achieved through two different directional electromigrations of Au silicide NWs along different orientations of two nonorthogonal 16 x 2 domains, which are driven by the electrical field of direct-current heating. Prospects for this Au silicide nanomesh are also discussed.

Atomically precise self-organization of perfectly ordered gadolinium–silicide nanomeshes controlled by anisotropic electromigration-induced growth on Si(1 1 0)-16 × 2 surfaces

“…2a. This coplanar double-domain Si(1 1 0)-16 × 2 surface is promising for use in the template-directed self-ordered growth of 2D nanomeshes [16][17][18]. This double-domain 16 × 2 reconstruction is not a facet [29], it is unlike the two-domain 2 × 1 reconstruction of the nominally flat Si(1 0 0) surface because the two domains of the Si(1 0 0)-2 × 1 surface are formed at a single-height atomic step.…”

“…To explore the driving force that controls the spatial uniformity of a self-ordered silicide nanomeshes on a Si(1 1 0) nanotemplate, we imitated the growth conditions of the Au-silicide nanomesh [16] to fabricate a well-ordered Gd-silicide nanomesh. The post-annealing temperature was increased to 850 • C to enlarge the growth mobility of Gd-silicide NWs and enhance the anisotropic electromigration effect.…”

“…Recently, we developed a template-directed 2D selforganization based on a double-domain Si(1 1 0)-16 × 2 surface [16][17][18]. A highly-integrated, well-ordered silicide nanomesh can be self-organized over a mesoscopic area by the heteroepitaxial growth of atomically identical silicide NWs on the periodic upper terraces of double domains on the 16 × 2 reconstruction [19,20].…”

Growth and magnetism of low-temperature deposited Fe/Si(111) films as an intermediate layer for suppression of silicide formation

“…The growth of magnetic materials, like Fe and Co, 1-7 on semiconductor surfaces, has attracted particular interest and been widely studied because of the potential applications combining magnetism and semiconductor techniques, so-called spintronics. 2,[14][15][16][17][18][19] In some cases, the buffer layer needs to be thick enough to block the chemical activity of the semiconductor surface. [8][9][10][11][12][13][14][15] The silicide formation not only randomizes the crystalline structure and electronic structure near the interface but also leads to a thick magnetic dead layer and unstable magnetic anisotropy.…”

“…2,[14][15][16][17][18][19] In some cases, the buffer layer needs to be thick enough to block the chemical activity of the semiconductor surface. With this idea of using LT-Fe as the intermediate layer, not only the planar Si surface, but also many recently developed Si-based nanostructures [18][19][20][21][22][23] can be used as suitable templates for magnetic material deposition without introducing new materials in between or destroying the nanopatterning on the substrate. 2 In other cases, deposition of submonolayer buffer atoms with high temperature annealing can result in a very stable superstructure on the semiconductor surface, providing a sharp interface for the subsequent deposition of magnetic materials.…”