Gd disilicide nanowires attached to Si(111) steps

TL;DR

This paper investigates the growth of Gd disilicide nanowires on Si(111) step arrays, demonstrating their formation, orientation, and attachment properties, which are promising for self-assembled electronic device connections.

Contribution

It presents a detailed study of Gd disilicide nanowire growth on Si(111), highlighting their morphology, growth conditions, and attachment to step edges, advancing nanowire fabrication techniques.

Findings

Nanowires are atomically smooth with large aspect ratios.

Wires grow parallel to steps in the [-1 1 0] direction.

Wires are always attached to step edges, enabling selective growth.

Abstract

Self-assembled electronic devices, such as quantum dots or switchable molecules, need self-assembled nanowires as connections. We explore the growth of conducting Gd disilicide nanowires at step arrays on Si(111). Atomically smooth wires with large aspect ratios are formed at low coverage and high growth rate (length >1 micron, width 10nm, height 0.6nm). They grow parallel to the steps in the [-1 1 0 ] direction, which is consistent with a lattice match of 0.8% with the a-axis of the hexagonal silicide, together with a large mismatch in all other directions. This mechanism is similar to that observed previously on Si(100). In contrast to Si(100), the wires are always attached to step edges on Si(111) and can thus be grown selectively on regular step arrays.