Co-induced nano-structures on Si(111) surface

Abstract

The interaction of cobalt atoms with silicon (111) surface has been investigated by means of scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED). Besides the Co silicide islands, we have successfully distinguished two inequivalent Co-induced $\sqrt{13}\times\sqrt{13}$ reconstructions on Si (111) surface. Our high-resolution STM images provide some structural properties of the two different $\sqrt{13}\times\sqrt{13}$ derived phases. Both of the two phases seem to form islands with single domain. The new findings will help us to understand the early stage of Co silicide formations.Comment: 4pages 4figure

reconstruction of the Co–Si(111) surface investigated by high-resolution STM and DFT calculations

“…Recently, Cui and al. have observed similar ffiffiffiffiffiffi 13 p domains with the coexistence of dark and bright clusters for Co deposited on a Si(1 1 1) surface kept at 800 K, but together with another type of ffiffiffiffiffiffi 13 p areas containing an ordered array of equivalent clusters [11]. Note that we never observed this latter ffiffiffiffiffiffi 13 p ordered array for room temperature depositions of Co with post annealing.…”

Investigation of semiconductor properties of Co/Si(111)-7 × 7 by AFM/KPFS

“…Magnetic properties appear when the Co coverage is sufficiently high [41][42][43]. However, the structure of Co-deposited Si surfaces is complex, and strongly affected by Co coverage and annealing temperature [44,45]. In our previous work, we have found interstitial Co atom adsorption and individual ring-like clusters (RCs) on a Si(111)-7 × 7 surface at a low Co coverage [46].…”

Adsorption and spin-related properties of multi-Co atoms assembled in the half unit cells of Si(111)-(7 × 7)

“…However, to further explore the potential application of aCo/Si (111) system, it is also important to findthe adsorption and magnetic properties of multiple Co atoms in a given half unit cell (HUC)on Si(111)-(7 × 7). Although a large numberof investigations ofCo reactions on aSi surface at high coverage and high temperature have previouslybeen carried out [10][11][12][13][14], both the initial Co adsorption stage and spin-related properties of multi-Co-atomconfigurations adsorbed on Si(111)-(7 × 7) at room temperature (RT) have been rarely investigated [10].…”

“…As a 3d ferromagnetic metal, cobalt atomsarehighly reactive with silicon. Deposition of cobalt atoms on Si(111)-(7 × 7) at high temperatures or annealing theSi substrate after Co deposition [10][11][12][13][14] leads to the formation of Co silicide compounds or clusters [12]. Boththeoretical and experimental studies indicate that cobalt silicides are non-magnetic [9,21,22].…”