Atomically precise self-organization of perfectly ordered gadolinium–silicide nanomeshes controlled by anisotropic electromigration-induced growth on Si(110)-16×2 surfaces

• Published in: Applied surface science 2015-09, Vol.349, p.49-58
• Main Authors: Hong, Ie-Hong, Chen, Tsung-Ming, Tsai, Yung-Feng
• Format: Article
• Language: English
• Subjects: Electromigration; Gadolinium silicides; Nanomeshes; Scanning tunneling microscopy; Self-organization
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.04.094

•This work provides a clear understanding of the template-directed self-organization mechanism of a perfectly ordered Gd-silicide nanomesh on a double-domain Si(110)-16×2 and identifies that the anisotropic electromigration is the driving force governing the two-dimensional self-ordering of the atomically precise silicide nanomesh.•The ability to self-organize a variety of the perfectly ordered silicide nanomeshes on Si(110) with atomic precision represents a promising route for the optimal bottom-up fabrication of well-defined crossbar nanocircuits, which opens the possibility for their utilizations in crossbar nanoarchitectures and Si-based magnetoelectronic nanodevices. Detailed scanning tunneling microscopy and spectroscopy (STM and STS) studies for the effects of thermal migration and electromigration on the growth of gadolinium–silicide nanomeshes on double-domain Si(110)-16×2 surfaces are presented to identify the driving force for the self-organization of a perfectly ordered silicide nanomesh on Si(110). STM results clearly show that the anisotropic electromigration effect is crucial for the control of the spatial uniformity of a self-ordered silicide nanomesh on Si(110). This two-dimensional self-ordering driven by the anisotropic-electromigration-induced growth allows the sizes and positions of crossed nanowires to be precisely controlled within a variation of ±0.2nm over a mesoscopic area, and it can be straightforwardly applied to other metals (e.g., Au and Ce) to grow a variety of highly regular silicide nanomeshes for the applications as nanoscale interconnects. Moreover, the STS results show that the anisotropic electromigration-induced growth causes the metallic horizontal nanowires to cross over the semiconducting oblique nanowires, which opens the possibility for the atomically precise bottom-up fabrication of well-defined crossbar nanoarchitectures.