Self‐Organization of a Highly Integrated Silicon Nanowire Network on a Si(110)–16 × 2 Surface by Controlling Domain Growth

Abstract

Here, bottom‐up nanofabrication for the two‐dimensional self‐organization of a highly integrated, well‐defined silicon nanowire (SiNW) mesh on a naturally‐patterned Si(110)–16 × 2 surface by controlling the lateral growths of two non‐orthogonal 16 × 2 domains is reported. This self‐ordered nanomesh consists of two crossed arrays of parallel‐aligned SiNWs with nearly identical widths of 1.8–2.5 nm and pitches of 5.0–5.9 nm, and is formed over a mesoscopic area of 300 × 270 nm2 so as to show a high integration density in excess of 104 µm−2. These crossed SiNWs exhibit semiconducting character with an equal band gap of ∼0.95 eV as well as unique quantum confinement effect. Such an ultrahigh‐density SiNW network can serve as a versatile nanotemplate for nanofabrication and nanointegration of the highly‐integrated metal‐silicide or molecular crossbar nanomesh on Si(110) surface for a broad range of device applications. Also, the multi‐layer, vertically‐stacked SiNW networks can be self‐assembled through hierarchical growth, which opens the possibility for creating three‐dimensionally interconnected crossbar circuits. The ability to self‐organize an ultrahigh‐density, functional SiNW network on a Si(110) surface represents a simple step toward the fabrication of highly‐integrated crossbar nanocircuits in a very straightforward, fast, cost‐effective, and high throughput process.

Observation of room-temperature negative differential resistance in Gd-doped Si nanowires on Si(110) surface

“…These dimensions are equal to those of clean SiNWs. 17 These results suggest that the dimensions and appearances of the SiNWs did not change after Gd doping, but the atomic structure of the doped SiNWs is different from that of the clean SiNWs.…”

“…16 Recently, we have shown that the long-range, periodic upper Si terraces of 16 Â 2 reconstruction on a Si(110) surface can be recognized as massively parallel silicon NWs (SiNWs) grown naturally on a Si(110) surface. 17 SiNWs have been widely used as the basic building blocks of several nanodevices (e.g., field-effect transistors, logic gates, and biochemical sensors), 18-20 and they can be directly integrated into Si-based chips by means of Si-compatible nanofabrication technology. Moreover, transition-metal doped SiNWs have been shown to exhibit room-temperature (RT) ferromagnetism or halfmetallic ground state.…”

“…Atomically clean Si(110)-16 Â 2 surfaces (heavily n-type doped, $1 X cm) were prepared by using well-established annealing procedures 17 and confirmed by STM observations. The massively parallel Gd-doped SiNW arrays were formed by depositing 0.01-0.1 ML (1 ML ¼ 9.59 Â 10 14 atoms/cm 2 ) of high purity (99.95%) Gd onto a single-domain Si(110)-16 Â 2 surface at 750 C at a deposition rate of $0.035 ML/min and subsequently annealing at 800 C for 30 min.…”

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.…”

“…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].…”